(Concurring).
Though I arrive at the same destination as the majority, I choose an alternative route to get there — a route which, in my view, is both less conceptually troubling and better supported by existing precedent.
Contrary to the majority opinion, I do not think that this case can be resolved by relying on the plain error doctrine. Taken together, the first two prongs of the plain error standard require the appellant to demonstrate that an obvious error of law occurred. See Olano, 507 U.S. at 732-36, 113 S.Ct. 1770. The majority, the parties, and the district court are of the view that it is a foregone conclusion that such an error occurred here. Their steadfast belief rests on the assumption that the district court’s jury instruction, which made punitive damages available against the City, directly contradicted the Supreme Court’s holding in City of Newport. According to them, City of Newport essentially stands for the proposition that punitive damages are unavailable against a municipality under § 1983.
Notwithstanding their belief, however, City of Newport never held that punitive damages are unavailable in a § 1983 action against a municipality. Rather, the Supreme Court ruled that “a municipality is immune from punitive damages under § 1983.” City of Newport, 453 U.S. at 271, 101 S.Ct. 2748 (emphasis added); accord Saldana-Sanchez v. Lopez-Gerena, 256 F.3d 1, 11 (1st Cir.2001) (characterizing City of Newport as holding that “as a general rule, municipalities are immune from punitive damages judgments when sued under § 1983”). Although this distinction may appear inconsequential, it is rather significant in light of the circumstances of this case. If the Supreme Court had held that punitive damages were unavailable against a municipality in a § 1983 suit, then a plaintiff would be filing a frivolous complaint were he to sue for such damages. See Fed.R.Civ.P. 11(b)(2) (requiring that the claims in a party’s complaint be “warranted by existing law”). However, the Supreme Court’s holding that municipalities are “immune” from punitive damages under § 1983 has slightly different implications. Immunity, whether qualified or absolute, is an affirmative defense that can be forfeited, if not asserted in a timely manner, or waived. See Cozzo v. Tangipahoa Parish Council — President Gov’t, 279 F.3d 273, 283 (5th Cir.2002) (ruling that absolute immunity is an affirmative defense that is forfeited if not pleaded); Guzman — Rivera v. Rivera-Cruz, 98 F.3d 664, 667 (1st Cir. 1996) (“Since immunity must be affirmatively pleaded, it follows that failure to do so can work as a waiver of the defense.”); O’Neill v. Krzeminski, 839 F.2d 9, 13 (2d Cir.1988) (holding that a municipality’s indemnification agreement with defendant constituted a waiver of its municipal immunity defense); Bell v. City of Milwaukee, 746 F.2d 1205, 1271-72 (7th Cir.1984) (holding that state indemnification statute waived municipal immunity defense with respect to indemnified judgments). Thus, whereas unavailability implies a limitation on damages altogether, immunity, in the doctrinal sense, is a defense that can be forfeited or waived.
In fact, in Saldaña-Sánchez, we allowed a plaintiff to seek discovery against a municipality on the claim that the city had waived its municipal immunity defense un*23der § 1983. 256 F.3d at 11-12. Our holding rested on the explicit assumption that the municipal immunity set forth in City of Newport is an affirmative defense that can be waived. See id. at 12 (noting that precedent supports the view that waiver of the municipal immunity defense is possible). Moreover, we questioned whether the city had forfeited its municipal immunity defense by failing to assert it at or before trial. See id. Saldaña-Sánchez thus demonstrates how permeable municipal immunity from punitive damages under § 1983 can be, both in terms of forfeiture and waiver.
In the instant case, the City never pled an affirmative defense of immunity in its answer and did not raise this defense at summary judgment or trial. The City’s failure to do so can reasonably be viewed as a forfeiture of that defense. See, e.g., Guzmán-Rivera, 98 F.3d at 667 (holding that the failure of a government official to timely assert an affirmative defense of qualified immunity under § 1983 at trial would forfeit the defense for trial purposes). I therefore cannot conclude that the district court committed plain error in charging the jury that punitive damages were available against the City. To hold otherwise would require me to adopt two seemingly implausible propositions: (1) that the Supreme Court’s holding in City of Newport was perfectly clear that no punitive damages are ever available under § 1983; and (2) that Saldaña-Sánchez, which supports the proposition that municipal immunity can be forfeited, was so obviously incorrect as a matter of law that the district court should not have relied on it. See generally United States v. Tur-man, 122 F.3d 1167, 1171 (9th Cir.1997) (“If the district judge would have to be clairvoyant to detect the error ... the error is not plain and defendant must object as a condition for having it considered on appeal.”).
Rather than delving into an abyss of implausibility, I hold firm to the view that the district court did not commit plain error in its jury instructions because the City failed to assert, and thus likely forfeited, its affirmative defense of municipal immunity from punitive damages.
The majority contends that “this [argument] is surely a matter of form over substance.” The majority elaborates on this point by offering a hypothetical: if the night before the jury instructions were given the district court judge had discovered the City of Newport opinion, “it is hardly likely that [the judge] would have authorized punitive damages.” I respectfully disagree and offer a derivation of the majority’s hypothetical to demonstrate my point: if the night before the jury instructions were given, the district court judge obtained a complete description of the state of the law- — that is, discovered the municipal “immunity” to punitive damages set forth in City of Newport and learned about our opinion in Saldañar-Sánchez, which explicitly discusses how the City of Newport immunity defense can be waived or forfeited — I am convinced that the judge would have instructed the jury that punitive damages were available, since the City failed to assert its immunity defense at any stage of the litigation.
Notwithstanding my unwillingness to find plain error, I believe that there is an alternative, and more principled, ground for striking the punitive damages award against the City. Ordinarily, a party who fails to raise a claim or a defense in the district court is prohibited from unveiling it in the court of appeals. See United States v. Slade, 980 F.2d 27, 30 (1st Cir. 1992). “This rule is deeply embedded in our jurisprudence, and we have invoked it with a near-religious fervor.” Harwood, 69 F.3d at 627 (internal citations omitted). *24However, every rule speaks of an exception, and this one is no different. In exceptional circumstances and to prevent a miscarriage of justice, this Court may relieve a party from his failure to timely assert an affirmative defense. See, e.g., Correa v. Hosp. San Francisco, 69 F.3d 1184, 1196 (1st Cir.1995); see generally La Guardia, 902 F.2d at 1013 (holding that “an appellate court has discretion, in an exceptional case, to reach virgin issues”).
In Harwood, we reached the merits of a legislative immunity defense even though the defendants failed to raise the issue in the district court. 69 F.3d at 627-29. We found it appropriate to reach the untimely immunity issue because: (1) the omitted issue was purely legal in nature; (2) the belated proffer raised an issue of constitutional magnitude; (3) the omitted argument was highly persuasive; (4) there was no inequity or special prejudice to the plaintiffs in allowing the defense to be raised for the first time on appeal; (5) the omission seemed entirely inadvertent; and (6) the omitted issue implicated a matter of great public concern. See id.; see also Krynicki, 689 F.2d at 291-92 (allowing a party to raise a virgin issue on appeal because (1) the issue was purely legal; (2) the omitted argument was highly persuasive; (3) the omitted issue was likely to arise again in other cases; and (4) the failure to address the issue would result in a miscarriage of justice).
Because I believe that these factors are more than adequately represented in this case, I would excuse the City’s failure to raise its municipal immunity defense below. First, whether the City should be immune from the $500,000 punitive damages award is a purely legal issue, cf. Hanvood, 69 F.3d at 627 (discussing the issue of legislative immunity as “purely legal in nature”), and the record necessary to resolve it can be developed no further. See La Guardia, 902 F.2d at 1013 (“[Whether] the point can be resolved with certitude on the existing record ... [is] a factor that often inclines a court to entertain a pivotal argument for the first time on appeal.”). Second, the omitted issue is highly persuasive — that is, if the City is allowed to raise its municipal immunity defense, it would undoubtedly prove victorious on the issue given the Supreme Court’s holding in City of Newport.
Third, Chestnut would not suffer any procedural inequity or special prejudice were we to address this issue.4 Plaintiff addressed the omitted issue in his brief and set forth his claims at oral argument. Cf. Singleton v. Wulff, 428 U.S. 106, 120, 96 S.Ct. 2868, 49 L.Ed.2d 826 (1976) (discussing importance, in determining whether to reach an omitted issue, of ensuring that the opposing party “ha[s] the opportunity to present whatever legal arguments he may have” to the court of appeals). Thus, the absence of unfairness weighs in favor of addressing the omitted issue.
Fourth, the City’s failure to raise its municipal immunity defense seems entirely inadvertent. Although the omission had the regrettable effect of prolonging the trial, it did not produce any tactical advantage to the defendant.
Fifth, and perhaps most importantly, the failure to address the City’s municipal *25immunity defense would result in a miscarriage of justice. “[P]unitive damages imposed on a municipality ... are likely accompanied by an increase in taxes or a reduction of public services for the citizens footing the bill.” City of Newport, 453 U.S. at 267, 101 S.Ct. 2748. It is convoluted and unfair to impose the burdens of a punitive damages award on the same taxpayers and citizens for whose benefit the wrongdoer was being chastised. See id. Punishing blameless taxpayers for the ineptitude of the City’s attorney is simply unjust, especially considering that the taxpayers are in no position to deter similar negligence in the future.
Because all of these factors converge in the City’s favor, I would excuse the City’s failure to assert its immunity defense below and proceed to address the merits of the defense. In City of Newport, the Supreme Court unequivocally held that municipalities are immune from punitive damages in § 1983 actions. 453 U.S. at 271, 101 S.Ct. 2748. Chestnut can advance no argument, and I cannot conceive of any, to attack this proposition. On this basis, I would find that the City’s defense precludes the punitive damages award in this case, and I would strike those damages.
I therefore concur in the outcome of the majority opinion.
. Though plaintiff would be stripped of his punitive damages award if the City is allowed to assert its municipal immunity defense on appeal, that prejudice is not the type contemplated by this factor. Rather, we examine whether the plaintiff would suffer any procedural unfairness if we address the omitted issue. See Hm~wood, 69 F.3d at 629 (stating that plaintiffs would not suffer any “special prejudice or inequity” by addressing the omitted issue, despite the fact that reaching the issue on appeal meant that the injunction that plaintiffs obtained in the lower court would be vacated).