The Patriots’ persecution industrial complex produces T-shirts, websites, and feelings of aggrievement. There is no NFL organization or fan base that grips a grudge or relishes retribution more. The binding belief is that the Patriots get treated unfairly and punished more harshly by the NFL because other clubs are envious of their success and some league personnel are rankled by what they perceive as organizational arrogance.

It’s easy to dismiss this as self-serving dogma, but it just got some ammunition from the NFL.

The latest evidence of a disciplinary double-standard was an NFL decision last Tuesday not to punish the Seattle Seahawks for omitting cornerback’s Richard Sherman’s knee injury from the league’s weekly injury reports this past season. The Seahawks are repeat rule-breakers, having been cited three times since 2012 for offseason practice rules violations, including one last June that resulted in the docking of a 2015 fifth-round pick. But the league let them off with just a written warning for fudging the injury report. It’s hard to believe that would have been the case if the folks in Foxborough turned the injury report into creative writing.

It’s probably just a coincidence that the only team to beat the Tom Brady-led Patriots this past season got off with a warning a little more than a week after commissioner Roger Goodell’s somewhat awkward interactions with Patriots owner Robert Kraft and Brady at Super Bowl LI and Patriots defensive coordinator Matt Patricia stepped off the team’s return flight in a T-shirt that indecorously depicted Goodell as a clown. Earlier reports had indicated the NFL was considering stripping the Seahawks of a second-round pick. Perhaps those reports were inaccurate because going from facing the NFL taking away a second-round pick to not even getting so much as a fine is the disciplinary equivalent of overcoming a 25-point, second-half deficit to win the Super Bowl.

An e-mail from the Globe to the NFL requesting further rationale for the Seahawks decision did not receive a response.

Unlike Deflategate, there was no probability attached to the Seahawks’ offense, no need to commission a multimillion-dollar investigation or conduct a prejudicial scientific study. Seattle broke the rules and admitted it — freely, if unwittingly.

In a radio interview with ESPN 710 in Seattle after the season, old friend/Seahawks coach Pete Carroll confessed that Sherman had dealt with a “significant knee [injury] the whole second half of the season, and it was a struggle to him to try to get out there.’’ Carroll said that it was the same issue that quarterback Russell Wilson had. Wilson suffered a sprained MCL in his left knee.

The problem was Seattle never listed Sherman’s injury on the injury report, citing days he missed practice as being “non-injury related.’’ The exception was a missed practice the Wednesday before a game against the Tampa Bay Buccaneers on Nov. 27 that was attributed to an ankle injury, according to the Seattle Times.

The Seahawks’ defense was that they misinterpreted the rule. If that sounds familiar it’s because that was Patriots coach Bill Belichick’s rationale for Spygate in 2007, when he and the Patriots were fined and the team forfeited a first-round pick for taping opposing teams’ signals from an unauthorized location.

That’s a penalty the team earned after foolishly ignoring a previous warning about prohibited filming. As significant as that penalty was, it could have been worse, and several owners in the league felt it should have been worse.

That sentiment contributed to the excessive penalty Brady and the Patriots received in the air pressure saga. Brady got a four-game suspension, which he served after a lengthy court fight. The Patriots were fined $1 million and lost a 2016 first-round pick and a 2017 fourth-round pick.

The NFL is a lot like high school with billionaire owners and inflated-ego NFL executives. There are grudges and petty squabbles that linger.

Like allegedly deflating footballs for your quarterback’s comfort, lying about an injury is a relatively venial offense that doesn’t dictate wins and losses.

The raison d’etre for the injury report is primarily for gambling purposes.

Finessing the injury report is standard operating procedure. Last season, the Indianapolis Colts, the team that blew the whistle on Deflategate, didn’t list a rib injury that affected quarterback Andrew Luck. Former Patriots cornerback Aqib Talib alleged that the Patriots misrepresented his injury during the 2013 season, listing him with a hip injury instead of a quad. The Pittsburgh Steelers didn’t list the groin injury that knocked Le’Veon Bell out of the AFC Championship game.

Still, that Pumped and Jacked Pete and the Seahawks got away without any punitive action is stunning when you consider part of the rationale for the Deflategate punishment was based on a strict interpretation of the sanctity of rules regarding the integrity of the game and competitive equality, as well as having priors.

NFL executive vice president of football operations Troy Vincent wrote in the letter detailing the Deflategate punishment: “ . . . Violations that diminish the league’s reputation for integrity and fair play cannot be excused simply because the precise impact on the final score cannot be determined. Here, there are several factors that merit strong consideration in assessing discipline. The first is the club’s prior record.’’

Seattle now has at least four violations since 2012.

The Seahawks were fined $400,000, Carroll was fined $200,000, the team was docked a 2017 fifth-rounder, and forced to forfeit its first week of OTAs after the NFL ruled in September that Seattle had violated the no-live-contact rule in an OTA session last June. In 2014, Carroll and the team were fined and the team lost two minicamp days for impermissible contact at offseason workouts. In 2012, Seattle had to forfeit two OTAs and an offseason workout day for allowing contact.

So, Seattle is a recidivist violator of relatively minor rules and sometimes pushes the limits in pursuit of victory. Sounds like a team I know.

Apparently, the NFL values the 12s, Seattle’s vociferous fans, more than TB12. The league should have either upgraded the fifth-round pick it took from Seattle to the club’s highest-ranking compensatory pick, expected to be a third-rounder, or taken away two picks.

Instead, Carroll and Co. walk away scot-free.

That just reinforces the belief that the Patriots represent the bull’s-eye when it comes to the dartboard discipline meted out by the NFL.

Christopher L. Gasper is a Globe columnist. He can be reached at cgasper@globe.com.