dissenting:
In this involuntary commitment case, the court reverses a jury verdict in favor of plaintiff Olivier because it concludes that no group of laypersons could have determined that the defendant doctors violated due process without “expert testimony to establish the relevant medical standards that were allegedly violated.” Supra at 190. I respectfully dissent.
1. Requiring Expert Medical Testimony to Pursue a Due Process Challenge to Involuntary Commitment
Preliminarily, I observe that I do not understand the court today to be holding that expert testimony is an absolute prerequisite to establishing a due process challenge to involuntary commitment. See supra at 190-91. Professor Wigmore notes that the law has rarely imposed such a “rule-of-thumb,” and he has wisely cautioned against its expansion. 7 Wigmore, Evidence § 2090, 579-90 (Chadbourn rev. 1978).10
*193In general, the law affords trial judges considerable discretion to admit or exclude expert evidence as appropriate to helping a jury perform its sworn role. See Salem v. United States Lines Co., 370 U.S. 31, 35, 82 S.Ct. 1119, 8 L.Ed.2d 313 (1962) (recognizing that “a trial judge has broad discretion in the matter of the admission or exclusion of expert evidence”). Indeed, because that determination necessarily “turns on a variety of factors readily apparent only to the trial judge,” a reviewing court should sustain “his decision to permit the jury to decide the case without the aid of experts unless the decision was ‘manifestly erroneous.’ ” Morgan v. District of Columbia, 824 F.2d 1049, 1061 (D.C.Cir.1987) (quoting Salem v. United States Lines Co., 370 U.S. at 35, 82 S.Ct. 1119 (reversing appellate ruling that jury could not decide issues of unseaworthiness and negligence without expert testimony as to proper marine architecture)). For reasons discussed more fully in the remainder of this dissent, I do not think the district court committed such error in this case.
2. Expert Medical Testimony Was Presented to the Jury in This Case
I cannot agree that no expert testimony as to medical standards was presented to the jury in this case. The district court specifically charged the jury that the defendant doctors and Dr. Ceus testified not only as witnesses to historical facts, but as experts, competent to render opinions on matters within their expertise. See Trial Tr. at 957-58. When, during the charging conference, the court stated that the doctors were “not expert witnesses within the meaning of Rule 26” of the Federal Rules of Civil Procedure, it explained that what it meant was that the witnesses had not been “retained by a party for the [singular] purpose of giving expert testimony.” Id. at 856. Nevertheless, it concluded that an expert-witness instruction was warranted because the doctors “did render opinions in the field of psychiatry.” Id. Given the considerable background and training *194all these doctors had in psychiatry, and specifically in New York’s involuntary commitment procedures, I do not think we can fault the district court’s recognition of them as expert witnesses. See, e.g., Nora Beverages, Inc. v. Perrier Group of America, Inc., 164 F.3d 736, 746 (2d Cir.1998) (noting that the district court has broad discretion to determine whether a proposed witness is qualified to testify as an expert, and its determination is reversible only for “manifest error.”)11
3. Further Expert Medical Testimony Was Unnecessary for the Jury to Resolve the Parties’ Dispute Regarding Defendant Doctors’ Disregard for the Established Legal Standard
In ordering reversal, the, majority observes that the defendant doctors, even if recognized as expert witnesses, testified only “as to the internal hospital procedures,” not “to community medical standards.” Supra at 191 n. 8. To my mind, this distinction is of no import because there was no factual dispute between the parties as to accepted medical standards. Rather, plaintiff -sought to prove that the defendant doctors deliberately or recklessly ignored the applicable legal standard for involuntary commitment, ordering his confinement even though they did not, in fact, believe that he presented a risk of danger to himself or others.
The legal standard for involuntary commitment of the mentally ill is well established and requires no expert testimony: “due process does not permit the involuntary hospitalization of a person who is not a danger either to herself or to others.” Rodriguez v. City of New York, 72 F.3d 1051, 1061 (2d Cir.1995) (and cases cited therein). Common sense dictates that due process cannot insist that danger assessments always be correct, but it does demand that involuntary commitment be ordered only “in accordance with a standard that promises some reasonable degree of accuracy.” Id. at 1062. To ensure such accuracy, New York law requires that assessments of dangerousness be made by licensed physicians. Id.; see also 7 Wig-more, Evidence § 2090, 588. But a physician’s finding of dangerousness cannot, by itself, satisfy due process. A physician’s judgment in ordering involuntary confinement must “be exercised on the basis of substantive and procedural criteria that are not below the standards generally accepted in the medical community.” Id. at 1063. In sum, in the context of involuntary commitments, due process has both a subjective and objective component. Before a mentally ill person is confined against his will, a physician must subjectively determine that he presents a risk of danger to himself or others, reaching that determination consistent with the objective standards generally accepted within the medical community.
Thus, in cases where a physician makes the necessary subjective determination of dangerousness, a plaintiff challenging that assessment for failing to comport with generally accepted medical standards may well need to present expert testimony as to those standards to raise a triable issue of fact. Cf. Rodriguez v. City of New York, 72 F.3d at 1063 (reversing summary judgment award in favor of defendants *195because parties’ conflicting expert opinions raised a question of fact as to whether accepted medical standards viewed “suicidal ideation” without more as a sufficient indicator of dangerousness to warrant confinement). But that is not this case. Olivier did not claim that his involuntary commitment violated due process at the objective level of analysis because the defendant doctors employed the wrong medical standard in making their dangefousness determinations. He claimed that the defendant doctors violated due process at the first subjective level by consciously disregarding their legal duty to make a dangerousness assessment. In short, they recklessly ordered his confinement even though they did not actually believe from the evidence before them that he presented the requisite risk of danger. Because this due process challenge turned largely on the jury’s assessment of the witnesses’ credibility, its resolution required no further expert medical testimony. See generally United States v. Forrester, 60 F.3d 52, 63 (2d Cir.1995) (“As a matter of law, the credibility of witnesses is exclusively for the determination by the jury”) (internal quotation marks and citation omitted); Bossett v. Walker, 41 F.3d 825, 830 (2d Cir.1994) (same); United States v. Shul-man, 624 F.2d 384, 388 (2d Cir.1980) (same).12
4. A Revieio of the Evidence in the Light Most Favorable■ to Olivier Indicates that the Defendant Doctors Violated Due Process by Committing Him Although They Did Not Believe that He Presented the Requisite Risk of Danger
Needless to say, the issue of whether the defendant doctors did or did not believe that Olivier presented a risk of danger when they ordered him confined was hotly contested at trial, with the parties presenting conflicting versions of the facts and vigorously challenging the credibility of each side’s witnesses. Had the jury resolved these conflicts in favor of defendant doctors, the record would not permit a court to second-guess that conclusion. But, on this appeal to overturn a jury verdict in favor of Olivier, we must examine the record in the light most favorable to him. In short, we must assume that the jury resolved all credibility disputes and drew all reasonable inferences in his favor. See Advance Pharm., Inc. v. United States, 391 F.3d 377, 390 (2d Cir.2004); Randall v. K-Mart Corp., 150 F.3d 210, 211 (2d Cir.1998). We may not set aside the judgment unless, upon such review, we *196conclude that “there is such a complete absence of evidence supporting the verdict that the jury’s findings could only have been the result of sheer surmise and conjecture.” Advance Pharm., Inc. v. United States, 391 F.3d at 390 (quoting Galdieri-Ambrosini v. Nat'l Realty & Dev. Corp., 136 F.3d 276, 289 (2d Cir.1998)); Randall v. K-Mart Corp., 150 F.3d at 211; Reed v. A.W. Lawrence & Co., Inc., 95 F.3d 1170, 1177 (2d Cir.1996).
Reviewing the record in this light, I must conclude that sufficient evidence permitted the jury to find that the doctor defendants confined Olivier on the basis of evidence they themselves believed to be insufficient to support a finding of dangerousness. The majoi-ity suggests that such a finding is insufficient to prove a due process violation because it would be “speculative to leap from this evidence to a conclusion that Olivier was committed for reasons other than the defendant doctors’ conclusion that he posed an imminent danger to himself or others.” Supra at 191-92. The majority also faults Olivier for “offering] no suggestion as to what such other reason might have been.” Id. I do not, however, understand it to be part of a plaintiffs burden in raising a due process challenge to involuntary commitment to prove that the defendants acted for non-medical or otherwise improper reasons. It might well be the medical view of some psychiatrists that confinement would benefit some mentally ill individuals who do not present an immediate risk of harm to themselves or others, but due process does not permit them to order such confinement against a person’s will. Thus, if the record, viewed in the light most favorable to plaintiff, supports a jury finding that the doctor defendants — for whatever reason— ordered Olivier’s commitment without believing that he presented the requisite risk of danger to himself or others, I think we must affirm the judgment in this case. Such a view of the record does support that jury finding as to each of the three defendant doctors.
a. Dr. Mohammed
On February 6, 2001, Monica Olivier went to defendant hospital’s Crisis Center seeking assistance for her brother, whom she feared was suicidal. Monica Olivier there explained to Dr. Mohammed that her concerns were based on a letter that her brother had written to his girlfriend. Although she had not herself seen the letter, Monica reported that another sister, Margaret, had told her the letter stated that her brother “couldn’t live in this condition anymore,” and that, if “something happened to him,” his children were to get certain items of property. Trial Tr. at 289. Dr. Mohammed also learned, however, that earlier that same day, at Monica’s behest, officials from the local sheriffs office and the college where Olivier was then enrolled had spoken to him, that Olivier had denied any thoughts of suicide, and that the officials concluded that no intervention was necessary. Further, Dr. Mohammed learned that Olivier’s girlfriend had spoken directly with Olivier after receipt of the letter in question, and she had telephonically reported to Mohammed’s nurse that Olivier had no intention of killing himself. Dr. Mohammed testified that based on his conversation with Monica Olivier, he nevertheless concluded that Olivier presented a sufficient threat to himself to warrant issuance of a “police letter” for his detention.
If we were to assume that Dr. Mohammed’s testimony was credited, it might have been helpful to the jury for Olivier to have presented expert testimony that, based on the evidence before him, Dr. Mohammed’s assessment of Olivier’s dangerousness fell below reasonable medical standards for the evaluation of mental illness.*19713 In fact, however, we must assume that Dr. Mohammed’s testimony with respect to his dangerousness conclusion was not credited. Monica Olivier expressly testified that Dr. Mohammed admitted to her that the facts before him were insufficient to permit him to make the dangerousness assessment necessary to support involuntary commitment:
[H]e basically said that he couldn’t issue a police letter based on what I had told him, because I didn’t actually see the letter. And he said maybe if my sister had talked to him, being that she was the one who had read the letter, or maybe if the girlfriend had talked to him or even showed him the letter, then he probably would have been able to issue a police letter, but he couldn’t because he said that my brother had rights, and he had no jurisdiction, basically, to violate them based on what I told him.
Trial Tr. at 734.
Further, Dr. Mohammed’s credibility was undermined by discrepancies between his testimony and that of Dr. Ceus regarding their telephone conversation on February 6, 2001. The majority notes that “exactly what Ceus said to Mohammed is unclear.” Supra at 186-87. I would agree if this court were being asked to resolve the sharp factual conflicts between these witnesses’ testimony. But that is not our task; on this appeal, we must assume that the jury resolved all credibility conflicts in favor of plaintiffs witness, Dr. Ceus. Thus, while it may be correct to note, as the majority does, that it is undisputed that Dr. Ceus did not specifically object to Olivier’s involuntary commitment in his conversation with Dr. Mohammed, see supra at 186-87, we must assume the jury credited Dr. Ceus’s explanation that he told Dr. Mohammed that he could not make that decision for him. Dr. Mohammed would have to reach his own conclusion. See Trial Tr. at 620-21, 624. Further, we must assume the jury found that Dr. Ceus did not “recommend[ ]” detention, as Dr. Mohammed wrote in his clinical notes, id. at 320, nor did Ceus ever “concur” in detention, as Dr. Mohammed testified at trial, id. at 325; see also id. at 620-21.
Assuming then that the jury rejected Dr. Mohammed’s testimony and credited Monica Olivier’s account, it could reasonably have found that Dr. Mohammed issued a police letter based on evidence that he himself admitted was insufficient to permit a physician to make the legally-required assessment of dangerousness. Under these circumstances, I cannot agree with my colleagues in the majority that further expert testimony was required to support a verdict in favor of plaintiff.
b. Dr. Gulati
Similarly, if the evidence pertaining to Dr. Gulati’s detention order is viewed in the light most favorable to Olivier, we must conclude that the jury discredited his testimony that he committed Olivier based on a professional assessment that plaintiff presented a substantial risk of harm to himself. See Trial Tr. at 364-65. Instead, we must assume that the jury believed Olivier when he testified that Dr. Gulati admitted to him that he did not “have any reason to keep you here. You seem to be fine.” Id. at 100-01.
Not insignificant to understanding the jury’s decision is the fact that Dr. Gulati’s *198credibility was undermined by inconsistencies between his testimony and that of a third sister, Marie Olivier, regarding their conversation pertaining to the need for detention. Although Dr. Gulati stated that Marie Olivier was afraid her brother was suicidal and “plead[ed] for keeping him overnight because she felt he was really unsafe to be released,” id. at 363, Marie Olivier denied that she made such statements, id. at 779. • She testified that, in fact, she implored Gulati to release her brother, telling the doctor that Olivier had seen Dr. Ceus shortly, before being brought to the Crisis Center by the police and “that he was fine and there was no reason for him to be up there.” Id.
Assuming, as we must, that the jury did not find Gulati to be a ’ credible witness and, instead, accepted Olivier’s account of the doctor’s concession, I do not think the jury needed further expert testimony to conclude that a doctor who ordered involuntary detention without “any reason” acted in reckless disregard of a person’s right to due process.
3. Dr. Padilla
As the majority recognizes, Dr. Padilla, who examined Olivier on February 7, 2001, acknowledged that she did not think he then presented a suicidal danger to himself, see supra at 187; nevertheless, she ordered his continued involuntary detention because- “he was agitated,” and refused to “contract for safety,” Trial Tr. at 450-51, 463. Here again, if this evidence had been uncontradicted, expert testimony might have assisted a jury to determine whether accepted medical standards indicated that agitation and a refusal to contract for safety indicated the sort of danger to self or others warranting confinement. But, as with Drs. Mohammed and Gulati, we must assume that the jury did not find Dr. Padilla credible.
Olivier himself contradicted Dr. Padilla’s account, testifying that she did not ask him to contract for safety on February 7. See id. at 112-13. Rather, this request was first made in the February 8 interview immediately prior to Olivier’s release, at which time he agreed to sign the proffered papers. See id. at 119-20. Assuming that Olivier did not refuse to contract for safety on February 7 and that Dr. Padilla did not believe him to be suicidal at that time, I cannot agree that a jury needed further expert testimony to conclude that involuntary commitment in these circumstances violated due process. ■
I note that Dr. Padilla’s credibility was further impeached by Olivier’s testimony that Padilla told him that she had spoken with-Dr. Ceus who told her that Olivier was suicidal. See id. at 114. Dr. Padilla also made an entry in Olivier’s records indicating that Dr. Ceus had told her Olivier’s letter to his girlfriend indicated that he thought he would be “better off dead.” Admission Note Feb. 7, 2001. Dr. Ceus testified that he never made any such statements to Dr. Padilla. See Trial Tr. at 626-27. Indeed, Olivier’s letter to his girlfriend, offered in evidence, did not contain any statement akin to that noted by Dr. Padilla. See PL Tr. Ex. 13.
Significantly, the defense, as part of its trial strategy, urged the jury to conclude that the letter exhibit was not the original written by Olivier to his girlfriend, but a document fabricated for trial. Further, the defense insisted that Dr. Ceus, whom it attacked as a persistent liar, was complicit in the scheme to manufacture evidence. In summation, the defense drew a bright line for the jury, arguing that a verdict for Olivier required the jury to find that the defendant doctors had all lied. See Trial Tr. at 946. This was plainly a risky strategy and, apparently, it backfired. Whatever reservations we may have about the *199credibility conflicts in this case, for purposes of this appeal, we must assume that the jury reached precisely the conclusion suggested by the defense in returning a verdict for Olivier.
In sum, assuming that the jury rejected the testimony of the defendant doctors and credited all the evidence offered by plaintiff, especially the evidence of concessions made by each of the three doctors that they did not, in fact, believe that plaintiff presented the requisite risk of harm to himself or others at the time they signed the challenged detention orders, I do not think we can conclude that the record was insufficient to support the verdict. Accordingly, I would affirm the judgment of the district court.
. One of the rare claims requiring expert testimony is medical malpractice. In Sitts v. United States, 811 F.2d 736, 739-41 (2d Cir.1987), a case relied on by the majority, see supra at 190, we recognized New York's expert-witness requirement for malpractice actions and ruled that the requirement applied regardless of whether malpractice actions were tried to a jury or to the court. But, as we subsequently made plain in Einaugler v. *193Supreme Court of the State of New York, “we did so in recognition of the fact that nearly one hundred years of New York [malpractice] cases specified such a requirement. In other words, the New York courts established this rule. We did not.” 109 F.3d 836, 841 (2d Cir.1997). In Einaugler, we declined to extend such an absolute expert-witness requirement to other actions in which the exercise of medical judgment was an issue. Specifically, we declined to hold that in a criminal case (where the prosecution’s burden would be proof beyond a reasonable doubt rather than the lesser preponderance standard applicable to civil cases), the prosecution was required to present expert medical testimony to prove a physician's reckless endangerment of a patient's life. Thus, while generally accepted medical standards may be relevant to both malpractice and due process challenges to involuntary commitments, I would not assume that the same expert-witness requirement applies to both claims.
Another rare circumstance identified by Professor Wigmore as requiring expert testimony is a commitment proceeding against the mentally ill or incompetent. See 7 Wigmore, Evidence § 2090, 587-90. It might well be expected that a free society would, at a minimum, demand that "on a proceeding to commit a person to restraint as mentally deranged or defective, the opinion of physicians must be adduced.” Id. at 588 (emphasis in original). But it does not necessarily follow that the same society would categorically refuse to hear a person’s subsequent due process challenge to that confinement without contrary expert testimony. Much would depend on the nature of the challenge.
Thus, I would impose no rigid expert-witness requirement to due process challenges to involuntary commitment. Trial courts may well decide that expert evidence is frequently helpful to the fact-finder in such cases. But where no such evidence is received, an insufficiency argument should not automatically succeed. Rather, a court must review the totality of the evidence to determine whether a plaintiff could or, as in this case, has proved a violation of due process.
. The majority notes, at supra 188, that plaintiff did not provide advance notice that he intended to elicit expert opinions from these witnesses. See Fed.R.Civ.P. 26. Defendants, however, raised no notice objection in the district court, either to the witnesses' testimony or to the district court's instruction. In any event, a district court may, in its discretion, forgive a notice omission that is harmless, see Fed.R.Civ.P. 37(c), and defendant doctors can hardly complain that they were harmed by plaintiff's reliance on their own testimony as to any relevant accepted medical standards.
. The majority suggests that the district court's charge presented the case to the jury only on a theory of objective reasonableness. Supra at 192 n. 9 The cited instruction asks the jury to consider whether Olivier was "detained for a longer period of time, if any, than was reasonably necessary under the circumstances.” Trial Tr. at 965. Because the sole contested issue in this case, however, was whether any detention was warranted, a jury finding that the doctors never subjectively believed that Olivier posed a serious danger to himself or others would have supported a conclusion that his involuntary detention was not "reasonably necessary” under the established legal standard. The majority further asserts that the district court used the same objective reasonableness standard when instructing the jury to consider "whether the defendant psychiatrists acted within or without the boundaries of their lawful authority.” Trial Tr. at 966. Because the doctors' "lawful authority” to order involuntary commitment required them (1) to find that a person presented a particular risk of danger and (2) to employ accepted medical standards in making that finding, a jury determination that the doctors never made the requisite finding would support a conclusion that they exceeded their legal authority without any need to consider the medical standard by which an actual finding of dangerousness would be judged.
. There is no reason to think such expert testimony could not have been obtained. See Rodriguez v. City of New York, 72 F.3d at 1063 (noting that a rational jury could have accepted the opinion of plaintiff’s psychiatric expert “that the generally accepted view of the medical community was that [suicidal] ideation without any manifestation of intent is not sufficient to pose a danger warranting emergency involuntary commitment”).