OPI in Denver/SD Monday Night game
 

Denver had the ball and Manning threw a touchdown pass to Eric Decker with about 4:50 left in the game. It was called back because of OPI on Decker.

It's at 5:25 in the video. Denver Broncos vs. San Diego Chargers highlights - NFL Videos

Doesn't show a good angle, but on TV they showed replays from right in front of the play and there was barely any contact by either player. Did anyone else see it when it happened?

I saw it. I didn't like the call either. I will say that they showed a replay from a different angle where there MAY have been some contact earlier in the play, slightly out of the camera range of the shot you posted. Was tough to tell and I'm not positive the ball was in the air at that point (it may have been, it was close). I wish we knew if that contact was what was called... because if it wasn't, I'm with you - nothing that happens on the clip you posted rises to the level of OPI.

And this may be one reason the NFL wanted a stable of reserve officials.