First, you could argue that the IVE test is technically a standard of review, not of proof, and that standards of review frequently prescribe deference to the initial decision. That is true. But the rationales behind deferential appellate review standards just don't apply to football. The law frequently mandates deference when the initial decision was entrusted to the discretion of an initial adjudicator—the referee on the field, in our example. But "judgment calls" like holding and unnecessary roughness are already unreviewable. Reviewable calls are up for scrutiny precisely because they are thought not to be discretionary. The law also mandates deferential review when the initial decision-maker is better able to ascertain the true facts. But nothing like that applies here. Although the on-field official will sometimes have the superior vantage point, surely the replay official—who has the benefit of multiple camera angles in high-definition and super slo-mo—will more often than not have better access to the truth.
What about the argument that the indisputable video evidence standard is needed to preserve respect for the officials? To start, fans don't expect perfection from the refs. And insofar as they might, respect is threatened less by reversal of the rare challenged call than by the fact that viewers at home, watching replays in HD, can see when the refs get it wrong. Moreover, a standard as demanding as "indisputable video evidence" predictably invites only partial compliance. Sometimes replay officials appear to go by the IVE rule, sometimes they don't. The refs' oft-remarked failure to apply this extremely demanding standard might provoke more disrespect than the initial error.
There's also the argument that de novo review would lead to inexorable delays. That case is weak as well. Under current NFL rules, each team gets only two challenges, though they earn a third if the first two are successful. If the standard were changed to de novo review, the league might face lobbying to increase that allowance, for fans and coaches might find it frustrating if exhaustion of a team's challenges prevented a review of a clearly reversible call. The outer limit here is the college game, where the replay booth reserves the right to review every play. But the NFL has steadfastly insisted that pursuit of greater accuracy must not be allowed to cause substantial delay—two years ago, for example, it cut the allotted time for review by one-third. For or better or worse, then, the likelihood that it would permit significantly more challenges is trivially small.
All that I have argued so far has been designed to show that the tools and analysis developed in the law can be of use to sports—that they can help reveal that the replay standard used in the NFL doesn't make much sense. Happily, football might be able to teach the law something as well.
After an on-field review, the replay official has two basic options: to reverse the initial call or not. When the call is not reversed, the referee sometimes says that the on-field call "stands," other times that it is "confirmed." This year's edition of the NFL Referees' Manual directs referees that the "only time you should announce 'the ruling on the field stands' is when there is not enough visual evidence to make a decision." In short, the "stands" and "confirmed" verdicts mean different things. The latter tells us that the initial call was correct; the former reports that it wasn't indisputably wrong.
Perhaps the criminal justice system should be reformed to communicate a similar difference. A criminal jury unable to conclude beyond a reasonable doubt that the defendant is guilty is instructed to acquit. It does so by announcing "not guilty." But why only one verdict of acquittal, not two? A jury could return a verdict of "innocence" if it believes, more likely than not, that the defendant was, well, innocent. A verdict of "not (proven) guilty" would be appropriate only when the jury believes the defendant isn't guilty beyond a reasonable doubt.
That's the way they do it in Scotland. If it's good enough for the Scots and the NFL, maybe it should be good enough for the American criminal justice system too.