Re: Would you flag this?
The rule bok does not use the term "excessive celebration." I'm pretty sure that's from college ball and seen on TV. That's OK, it works, but the rule book just says "any delayed, excessive or prolonged act designed to focus attention upon himself." No further definition of any of those terms is there, which is why the interpretations very so wildly.
I don't think I've ever called it. The only celebrations I've ever flagged were right in an opponent's face. I think we can all agree that you have to step back or get up off the guy before you yell and scream.
In the video, I'd flag it as being prolonged. The DE made a great play and he should be jacked about ti. The first part of his dance, so long as it wasn't directed toward the opponent (and it wasn't) was OK, but he needs to get on with his day. By the time he draws back the invisible bow and fires an arrow, he went over the line.
A comment on the college rule -- I think it's a little ridiculous, but the NCAA rules committee is made up of COACHES. They write the rules how they want it called. Officials are enforcing the rules the coaches write. The SEC, more than any other conference, wants that stuff wiped out of the game. When I first heard about that play, I didn't know which teams were involved but I guessed it was an SEC game. That's the way the coaches there want it called, or else it wouldn't be called like that.