On the one hand, Atlanta definitely choked. By my definition, a “choke” happens when you’re in command of the outcome, and you let the moment overcome you, so that you don’t perform at the level you had been up to that point. In the case of the Falcons, the signs of the choke are subtle, but they are there, and a lot of it happened among their coaching staff.
Examples abound. On the fatal third down on their last meaningful drive (ignore the drive at the end), right after the sack of Ryan, the announcers were noting that the Falcons were still within field goal range. But Kyle Shanahan is already on record as saying that he made the call for a pass play there because they needed to get back in field goal range. That’s incredibly poor thinking, a lack of having at the front of his brain the most basic yardstick for late-game management: where your kicker can make a field goal from. That’s a choke.
On the prior play, the Falcons call a pass (when everyone knows that the better call is a run to run time off the clock). The call is not a choke per se. But when Ryan drops back to pass, he has to have one thought in his mind: don’t get sacked. Yet when the play starts, and he’s dropped deep to set up, the front line is already crumbling in front of him, and he has time to throw the ball to his left ahead of #12, but instead he reacts late to the onrushing Patriot and ends up being sacked deep behind the line. That’s a choke. That’s entirely on him.
There are, I think, other indications. My recollection is that during the 4th quarter, Atlanta wasn’t always good about running the clock down as far as it could before snapping the ball. On the final kickoff they received, with just under a minute left, Gostkowski kicks the ball just into the endzone, and the return man, instead of just catching it and taking the knee (giving the Falcons the ball at the 25 with no time off the clock), attempts to run it out. He gets stopped at about the 10. Two completions later, the Falcons were down to about 20 seconds and were only at the 27, roughly where they would have started the drive from had there been a touchback. These are all signs of choking under pressure.
On the other hand, New England totally changed how they were playing during the final 17 minutes of the game. The turning point was the botched onside kick. Up to that point, the Patriots were not firing on all cylinders. After that, they were much, much better. Brady was 20-25 in that time frame, and I don’t think the Patriot receivers had a drop in that spell, either (they had numerous drops earlier). The defense, which had not been putting that much pressure on Ryan, started making it uncomfortable for him in the pocket, and managed to force a fumble and a couple of sacks (both of which helped cause the Falcons to punt instead of trying to score), as well as forcing the Atlanta line to start holding (two holding penalties in that time frame, both of which cost Atlanta field goals). In short, New England got challenged by their sloppiness, and they responded in an excellent way. Had they not done so, the efforts of Atlanta to choke it away would not have been successful.