During the first segment of Patriots coach Bill Belichick’s appearance on The Late Show with David Letterman, it seemed that the host would be avoiding completely the still-pending #DeflateGate investigation regarding whether the Patriots tampered with air pressure in footballs during the AFC title game. In the second segment, Letterman did Belichick even more of a favor.

Letterman consistently downplayed the controversy, eventually dubbing the entire situation “nonsense.”

Dave had the perfect opening to push the issue early in the interview, when Belichick said of the victory over Letterman’s favorite team, the Colts, “Well, it was only a 38-point win.”

Letterman could have said bitingly in response (as he’s done with countless guests over the years), “Well, you also used deflated footballs.”

He didn’t, deferring all questions on the topic until the show returned from a commercial break. And when Letterman finally brought it up, he seemed reluctant to do so, testing the waters by lobbing a few softballs via a meandering question that ultimately wasn’t a question but a statement.

“That was the game by the way with the football nonsense,” Letterman eventually said. “And I’m telling you from the beginning I loved it because I knew a pound here in a football, a pound there is not gonna make a difference. 45 points. You know what I’m saying? I just thought, pick on something else. It’s like the goal posts were too narrow. It just doesn’t make any sense. And then you said, ‘Well I don’t know anything about inflated footballs.’ And why would you?”

Said Belichick in response, “I learned a lot in the next few days. I never realized there were so many Patriots fans that were scientists and physicists and college professors that understood it that well. We learned a lot in a hurry. I should’ve got a college credit for that.”

Letterman then tried to laugh the whole thing off with one of his canned-ham-style turns of phrase: “You know exactly what happened. I know you know exactly what happened. You know I know you know. And what it was was some kind of horseplay. Am I right?”

“No,” Belichick said. And then Letterman laughed and slapped the desk.

“Wait a minute,” he said. “I was told it was horseplay.”

Letterman then explained that they tested footballs by putting difference amounts of air pressure in them.

“One was inflated properly,” Letterman said. “One was not inflated properly. The difference is palpable, but it wouldn’t make any difference in a game.”

“Well we all know that as the footballs get colder, they deflate,” Belichick said. “Scientifically.”

“But there was only only one football that was deflated by two pounds,” Letterman said. “The others were deflated by what you would expect being outdoors.”

Those facts still haven’t been established with certainty, and they won’t be until the investigation by Ted Wells ends. But it was part of the broader “this is all a load of crap” narrative that Letterman opted to push.

“And then you got the kid going into the bathroom,” Letterman said. “He’s in there for 90 seconds. I can’t remember the last time I took a leak in 90 seconds. Are you that age where you have that problem?”

The host then reiterated his position that the whole thing would lead nowhere.

“I knew it would come to nothing and I knew it had no effect on the game and you could tell in your tone in the press conference and then Tom Brady also in the press conference you could tell that it was nonsense,” Letterman said. “Now where did it come from? You know where it came from. Did it come from my Colts? Is that where it came from?”

Of course it did, because the NFL already has acknowledged that Colts G.M. Ryan Grigson alerted the league to the concern during the game. But that was just the setup for Dave’s attempt to advance the conspiracy theory that makes his favorite team the villain.

“Here’s what I heard,” Letterman said. “I heard that the guy intercepts the pass, and he takes the ball over, hands it to his guy. He deflates it, and then they say, ‘Hey, look at this ball, it’s go no air in it.’ Is that what happened?”

“We’re gonna bring you in to testify when we get the investigation next month,” Belichick replied with a smile.

Belichick smiled a lot during the interview. And he should have; it’s a comedy show. But it was still Belichick’s first (and probably only) one-on-one interview, and it gave Letterman a prime opportunity to ask at least one or two meaningful questions under the guise of cracking wise.

His efforts, however, weren’t focused at all on advancing the ball, moving the needle, or getting to the truth, with sarcasm or wit driving the bus. Letterman operated under the premise that the entire situation is a joke, that nothing improper happened, and that if it did it doesn’t matter because even though the difference between a properly inflated ball and a deflated ball is “palpable,” using deflated footballs “wouldn’t make any difference in a game.”

The NFL sees it differently. Whether it made a difference or not, proof that anyone from the Patriots tampered with the footballs could result in significant punishment. Letterman’s failure to understand that, or his conscious decision to disregard it, squandered a prime opportunity to get something fresh, tangible, and/or informative out of Belichick.