One of the things I've been noticing a lot lately, is that defensive backs are able to unrealistically react to passes. It is practically impossible for a db to be in coverage with receiver A, and then to react to a pass thrown to receiver B and be able to defend the pass.
Here's an example:
https://ncaa.myfootballnow.com/watch/682#119069
Additionally, I've seen a lot of ***** thrown to a receiver in the middle of the field in single coverage, and by the time the ball arrives there are 3 (or more) defenders on the spot. Such reaction time is impossible.