Continuity mistake: When Dale and Brennan are in the bedroom after their parents just told them that they are selling the house, Dale is sitting on the bed with the mask on. In some of shots, his legs go from being crossed to different positions and sometimes they are flat on the bed. Also, as Brennan sings and Dale is on the side of his bed, his legs change positions.
Continuity mistake: In the first scene of Dale and Brendan climbing on to the gilded lady when it is in the tree, when they're climbing up the ladder and shout "pirate hats!" there's a man visible in the background, but a couple of shots earlier when they walked out of the house there's an overhead shot showing no-one nearby.
Continuity mistake: When the Billy Joel cover band is performing at the Catalina Wine Mixer, the guitarist is using a Divided by 13 head/cab. This is the green amp located by the drum riser. However, when Dale and Brennan take the stage, the amp has changed to a green Mesa/Boogie Stilleto Ace combo. You can see the Divided by 13 in the shot after the musicians have left, when Robert is explaining how he wanted to be a dinosaur behind Brennan's back, which shows that it wasn't moved by the musicians.
Continuity mistake: When Brennan and Dale first meet, they are standing on the front lawn and they tell each other that they have to be called a certain nickname. When the camera is zoomed back, it shows them really far apart from each other. When it shows Brennan's or Dale's point of view, they are closer together.