Continuity mistake: When James Franco is talking about jizzing all over Danny McBride, the camera goes behind Seth Rogan and you can blatantly see him laughing, then milliseconds later when the camera moves, his face is serious.
Continuity mistake: At the start, two arriving pilots approach the camera. Neither are wearing glasses. The shot reverses and as the pilots walk away the first officer (three stripes) is now wearing glasses.
Continuity mistake: In the last scene, wherein Seth and Jay meet Craig in Heaven and then party with the Backstreet Boys, their angel halos are entirely inconsistent, appearing and disappearing from one camera cut to the next.