Continuity mistake: When Jay is sitting in the patrol cart with his partner eating ice-cream, the amount of the partner's ice-cream that has melted keeps changing from shot to shot. Sometimes the ice-cream has melted a little bit, sometimes it has melted over his fingers, sometimes it hasn't melted at all. Jay's ice-cream also changes just as often, but is not as obvious. (00:09:20 - 00:10:25)
Continuity mistake: In the scene after Luke tips the contents from the box onto the table, when he puts the box upright after tipping it, there is a white hose hanging over the edge. But in the shot when the box is visible again, the hose is on the table. After that when you see the box again, the white hose is once again hanging on the box, but in a different position than it was originally. (00:08:40)
Answer: He has seen himself dancing, and is mortified at how bad he looks.