Continuity mistake: At the wedding, Rory puts his arm on Sam's shoulder. When Sam is mid-sentence ("For better or worse"), Rory's arm disappears at the cut. (00:06:50)
Continuity mistake: When Bon Jovi gets slapped, his two necklaces change positions (not from the slap, but when he is just standing still).
Revealing mistake: In the scene when they are travelling in the RV, the tea in the glass is perfectly still, even when the RV is obviously in motion. The tea should be jiggling in the glass.