"I thought they [were] about to run the ball, so I was anxious," Parker said after the game. "We kind of work on that, hard count, and he got me."
Bills quarterback Ryan Fitzpatrick came to the line and barked out signals, then hesitated before restarting his cadence. That seemed to be a clear sign that Buffalo had no intention of running a play from their own 49-yard line with the Eagles within seven points.
But Parker twice told reporters he believed they might run a play.
Parker had fought hard to even be available for the game. A high-ankle sprain suffered in Week 2 had limited him in practice until Friday.
"It hurts, but talk about [Parker] being a warrior. They didn't even know he was going to be able to play today," said defensive coordinator Juan Castillo. "He came out, and he's a warrior, you know. One play doesn't lose a game. I have to do a better job in the first half."
Indeed, the Eagles had five turnovers and a miserable first half defensively to contribute to the loss. Even if Parker had stayed disciplined, there was no guarantee that the Eagles would have scored to tie the game.
But Parker did fall victim to a trick so old it had Buffalo reporters asking Fitzpatrick if he thought it could work.
"Oh yeah," he said. "It's a play we work on all the time."
Coach Andy Reid refused to assign blame.
"I'm not going to hang one guy out to dry on that play," he said.
Added defensive end Jason Babin: "There isn't one person blaming Juqua at all. That's an extremely tough play. I know he feels bad about it, and it's just the way football goes. But it's not one play that loses the game."
That's true. But Parker's offside was the last meaningful snap of the game. And for Eagles fans, it was another sickening moment in four weeks full of them.
Contact staff writer Jonathan Tamari at 215-854-5214, firstname.lastname@example.org, or @JonathanTamari on Twitter.