Let's see, the officials missed a RTP call on Favre. They missed one the week earlier when Warner received a pretty obvious blow to the head. They also missed Sanchez getting wiped out on a running play (Not any sort of option play, but a normal, hand-it-off-and-watch, running play. I don't think I've seen a hit like that outside of the movies, where they try to show how dirty one team is).
The refs are going to make bad calls or miss calls in almost every game, some of them so obvious that you can't see how they messed it up. It's unfortunate that it cost the Vikings, but, short of reviewing every play, we're going to have to put up with human error from the officials.