Ryan Clark reacts to the NFC Championship Game's controversial ending, saying that Nickell Robey-Coleman should have been flagged for pass interference. (1:05)

Above all else, NFL replay is designed to save the league from itself. Its goal is to correct clear and obvious mistakes.

But when a clear and obvious mistake occurred late in the fourth quarter of Sunday's NFC Championship Game between the Los Angeles Rams and New Orleans Saints, there was nothing the replay system could do.

Referee Bill Vinovich's crew missed an obvious pass interference call on Rams cornerback Nickell Robey-Coleman, a painful reminder that such calls are not reviewable under current NFL rules. That must change, and there is a chance it will happen this offseason. Remember, most NFL rule modifications are usually reactions to massive controversies.

"We go into these league meetings and we sit as an ownership group and we don’t further evaluate the replay system," Saints coach Sean Payton said after the game. "We’ve got plenty of technology to speed things up. Look, I’m on the competition committee, so hopefully that provides a voice. But, man, I hope no other team has to lose a game the way we lost that one today."

Owners have long been reluctant to expand replay to include penalties and especially judgment calls such as pass interference. Their goal always has been to limit replay to objective decisions. Was a player down by contact? Did he land in bounds? Was he over the goal line? And to this point, owners have wanted subjective calls to remain an on-field, real-time judgment without the help of technology.

In most cases, that's understandable. Pass interference is in essence a judgment of whether a defender materially prevented a receiver from catching the ball in an illegal way. An official must judge whether contact was forcible or incidental. Was it initiated by the defender or was it a collision? Judgment from a replay official would be no less subjective and, in most cases, would force the play to be re-officiated in the booth.

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But officials are human, which means sometimes they are just going to make mistakes that can be seen by everyone but them. Longtime NFL coach Mike Holmgren, a former member of the competition committee, famously favored replay because it could correct mistakes that 50 fans in a bar could easily identify.

That's the argument for adding pass interference to replay. Although it would be a significant step, allowing replay to determine whether the call was justified or if an obvious foul was missed would not bring down the republic. How do we know that? The Canadian Football League has allowed pass interference to be reviewed since 2014. Last time I checked, the league was still in business. In fact, it imposed pass interference after a no-call late in the 2015 Grey Cup, ensuring a credible outcome.

The CFL has adjusted the rule a few times based on experience. In 2018, coaches have only one challenge at their disposal. They challenged 42 defensive pass interference calls, and of that total, 20 were overturned.

That's hardly a massive disruption to the game, another concern expressed whenever the subject of replay expansion occurs. There would be no reason to add additional challenges to an NFL coach's allotment -- two initially, with a third added if he wins the first two -- and reviews that occur during the final two minutes of the half are generally quick.

The bottom line is that the NFL has the technology, capacity and now the urgent incentive to add pass interference to replay. The point would not be to re-judge close calls in slow motion. It would be to avoid precisely the debacle the NFL encountered Sunday.

Put simply, this no-call almost certainly determined which team would represent the NFC in the Super Bowl. Careers and legacies were impacted.

Sunday already was a bit of a perfect storm. Vinovich's regular-season crew threw the fewest flags per game (13.1) in the NFL, and generally speaking, postseason crews tend to allow much more physical play in the defensive backfield. Chances are this type of situation wouldn't arise as much as traditionalists might fear.

But there has to be a safety net for use in emergencies to maintain credibility and faith in the outcome of NFL games. The infrastructure already exists. Now the NFL must find the will. If Sunday's debacle won't spur it, what will?