A party that really blew it gets not only a second but a third chance to correct his mistake

Last reviewed: September 2026

A New York court may permit a late expert affidavit, but submitting it is not the same as obtaining permission to have it considered. Mallards Dairy illustrates a request that succeeded: counsel supplied an explanation, the court granted leave and the other side received an opportunity to respond.

This was an engineering-services dispute over a leaking manure-storage pond, not a personal-injury action. Its motion-practice lesson can be relevant in injury litigation, but the factual setting and full appellate result should remain clear.

Legal update: The 2010 decision predates the current expert-exchange language in CPLR 3212(b). The statute now bars rejecting a summary-judgment expert affidavit merely because the CPLR 3101(d)(1)(i) exchange was not furnished before the affidavit. That is a different defect from missing an opposition deadline. CPLR 2214(c) still requires good cause for departing from its paper-submission rules. See the CPLR 2004 guide for extensions.

The case and the request for late expert proof

Mallards Dairy, LLC v E&M Engineers & Surveyors, P.C., 71 AD3d 1415 (4th Dept, March 19, 2010) arose from a contract for engineering design and inspection services. After the pond leaked, the owner sued on negligence, contract and warranty theories.

The defendant supported summary judgment with an expert affidavit. The plaintiff served opposition three days before an adjourned return date, without an expert affidavit. Thirteen days after oral argument, its lawyer sought permission to submit the missing expert proof.

The court allowed the late affidavit and a defense reply affidavit. The Fourth Department upheld that exercise of discretion. It nevertheless modified the order to dismiss the warranty causes of action because the agreement was for services. Acceptance of the affidavit did not mean the plaintiff defeated every branch of the motion.

The reasoning preserved in the original note

The original case note reproduced this part of the opinion. It addresses permission, the explanation for delay and the opportunity to respond:

Defendant contends on appeal that the court erred in considering plaintiff’s untimely expert affidavit. We reject that contention. “While a court can in its discretion accept late papers, CPLR 2214 and 2004 mandate that the delinquent party offer a valid excuse for the delay’ … Additional factors relevant when essentially extending the return day by accepting late papers include, among others, the length of the delay and any prejudice” (Associates First Capital v Crabill, 51 AD3d 1186, 1187, lv denied 11 NY3d 702; see generally Foitl v G.A.F. Corp., 64 NY2d 911, 912-913). We conclude that the court neither abused nor improvidently exercised its discretion in considering plaintiff’s untimely expert affidavit. Although the delay was approximately five weeks after the date on which the opposing papers were due, plaintiff specifically requested and was granted permission to serve the late affidavit (cf. Matter of Gustina, 135 AD2d 1124, appeal dismissed 72 NY2d 840, rearg denied 72 NY2d 953). Plaintiff’s attorney offered an excuse for the delay (see e.g. Associates First Capital, 51 AD3d at 1187-1188; Radaelli v City of Troy, 229 AD2d 882, 883), and any prejudice was alleviated when defendant was permitted to submit a reply affidavit in response to plaintiff’s late submission (see e.g. Vlassis v Corines, 254 AD2d 273; Kavakis v Total Care Sys., 209 AD2d 480).”

Jason’s original March 2010 analysis

Jason’s reaction to the sequence is preserved below. Read his discussion of the denied motion with the partial appellate modification described above.

Here is my summary of this one. An attorney alleges he was sandbagged and short served. Fair enough, it happens all the time. The attorney presumably had a chance to adjourn the matter, but instead submits papers that are tardy. Strike one. His papers are missing an expert affidavit even though the issue presumably requires same. Strike two. Now this is where it gets really bizarre. Attorney contacts chambers two weeks after the papers are submitted and requests to include an expert affidavit to supplement his motion. This is so despite his acknowledgment to Supreme Court that he did not think he needed an affidavit. Even stranger: the court grants the request. The movant, however, is allowed to put reply in, and it is assumed that this removes any taint or prejudice from this issue. Yet, the movant is probably screaming bloody murder and something else.

More good news: The motion is denied since the conflicting expert affidavits raise a triable issue of fact. What is even stranger is that the Fourth Department condoned this procedure.

By the way, does all of this sound familiar?

Three expert issues that should not be conflated

The deadline for the affidavit. Determine when opposition was due and whether the court has authorized a later submission. CPLR 2214(c) supplies a good-cause route for the court to direct otherwise. CPLR 2004 addresses extensions where another law does not expressly prescribe a different limit. Neither provision means that uploading a late affidavit automatically cures the timing problem.

The prior expert exchange. CPLR 3101(d)(1)(i) concerns disclosure of expected trial experts and their anticipated testimony. CPLR 3212(b)‘s current protection against rejection for lack of a prior exchange should be read for the defect it addresses. It does not say an expert affidavit can be served whenever counsel chooses.

The substance of the opinion. Timeliness and disclosure do not establish that the expert’s reasoning is sufficient. The affidavit still has to address the issue for which it is offered and support the requested result. Permission to submit a paper is not a judicial finding that its conclusions are correct.

A useful review separates those questions before drafting the argument. Otherwise a brief may cite the right statute for the wrong objection.

A 2026 example: the expert’s qualifications still matter

In Leuterio v Bradley, 89 Misc 3d 1239(A), 2026 NY Slip Op 51206(U) (Sup Ct, New York County, July 28, 2026), a medical malpractice plaintiff sought protection from disclosing not just her expert’s name, but qualifications, training, certifications and specialties. The court denied that request on the showing made.

The court explained that the 2015 amendment to CPLR 3212(b) addressed the timing of an expert exchange. It did not dispense with the information needed to evaluate the expert’s qualifications. The court distinguished withholding the name from withholding the other information and directed specified disclosure.

This is a trial-court decision about a protective order, not an appellate ruling granting permission for late opposition. Its usefulness here is the distinction between a timing protection and the adequacy of expert information. It should not be cited as though it decided the merits of the malpractice claim.

For a lawyer reviewing an expert submission, ask what objection is actually being raised. Is it the absence of an earlier exchange, the omission of qualifications, failure to comply with a particular order, or the affidavit’s reasoning? An answer to one objection may leave the others unresolved. Read the underlying order before assuming that the statute has displaced every disclosure obligation in the case.

Review the affidavit against the motion it must answer

The practical review should start with the proposition for which the affidavit is offered. Identify the issue raised by the moving papers and the evidence the expert has actually considered. Check that referenced exhibits can be found in the submitted record and that the opinion addresses the relevant event or treatment, rather than a generalized description of professional practice.

Counsel should distinguish an expert’s factual assumption from an established fact. If the assumption is disputed, identify the record support and the dispute instead of presenting counsel’s preferred version as conceded. An application for leave to submit the affidavit does not itself resolve those conflicts.

Also compare the proposed affidavit with the earlier disclosure and any court directions. A change in the subject of the opinion may call for an explanation beyond why the document arrived late. These are file-review steps, not a claim that Mallards Dairy approved every kind of supplementary expert opinion. They help keep the request tied to the actual paper the court is being asked to read.

Explain why the affidavit was not ready

The request should give a chronology, not just describe the motion as a surprise. Identify when the moving expert’s affidavit was received, when counsel recognized that responsive expert analysis was needed and what was done next.

The fact that the affidavit is now available helps identify the proposed submission; it does not, by itself, explain the missed deadline. If there was a misunderstanding about whether expert evidence was necessary, describe it accurately rather than attributing the problem to an adversary without support.

Counsel should also distinguish an unavailable expert from missing facts. CPLR 3212(f) addresses a showing that facts essential to justify opposition may exist but cannot then be stated. The relief requested and supporting explanation should fit the actual problem. A general desire for more preparation time is not the statutory showing.

These are practical drafting points. The 2010 court accepted the excuse on its record; that does not make the same explanation sufficient in every later case.

Give the other side a meaningful response proposal

In this case, the opposing party was allowed to answer the late expert affidavit with its own reply affidavit. That opportunity was part of the court’s analysis of prejudice.

For a current application, identify the exact additional paper and what subjects it addresses. Explain whether the adversary would need a new expert response, additional records or more time. Offer a realistic schedule and acknowledge any effect on the existing calendar.

From the other side, separate out the objection of untimeliness from the objection on substance. And then if the court grants permission, make sure you get a usable opportunity to respond rather than assuming that your objection of lateness preserves every evidentiary issue. Then keep the order and the papers that the court actually looked at identifiable in the record.

This is not a rule that reply permission eliminates every form of prejudice. A particular late submission may raise problems that a short response period cannot cure. The request and objection should address those problems specifically.

A late affidavit is not a late summary-judgment motion

CPLR 3212(a) governs the time to make a summary-judgment motion. It allows a court-set deadline within its terms and, where none is set, generally requires the motion within 120 days after the note of issue unless leave is granted for good cause.

That is separate from whether a paper opposing an already pending motion will be accepted. Mallards Dairy should not be cited as permission to miss the deadline for making the motion itself.

Similarly, a late affidavit is different from a request to adjourn a trial because an expert cannot attend. The Middle Village, Brooklyn Chiropractic and Normandin notes address witness scheduling on their own facts. Use the procedural route that corresponds to the act for which more time is needed.

What the later decisions add

Elusma v Jackson rejected a vague explanation of law-office failure for late opposition. Even then, the motion failed because the moving defendants had not carried their initial burden. The excuse question and the merits question remained separate.

Lannon v Everest National Insurance Co., 248 AD3d 1018 (2d Dept, April 15, 2026) confirms the court’s good-cause discretion under CPLR 2214(c), including whether to accept a surreply. It also recognizes that unauthorized surreplies introducing new arguments generally should not be considered. Neither decision turns supplementary submissions into a routine extra briefing round.

The useful comparison is therefore between records: what explanation was supplied, what permission was obtained, what prejudice was addressed and whether the underlying motion was supported. That comparison is more reliable than treating Mallards Dairy as a general promise of procedural forgiveness.

Reviewing an expert-affidavit problem

For a procedural issue in an injury case, gather the scheduling orders, motion papers, proposed expert proof and communications explaining the delay. The firm’s personal injury practice and contact page provide a route for discussing the record. No result follows merely from resembling a reported case.

Connect to the Encyclopedia

The CPLR 2004 extensions-of-time hub separates deadline extensions from witness scheduling.

• Elusma: a vague excuse and a deficient summary-judgment motion
• Counsel Financial: no opposition after an extended deadline
• Middle Village: diligence in arranging trial experts
• Brooklyn Chiropractic: a concrete witness-availability conflict
• Normandin: a brief continuance to finish expert testimony