Corrected entry: How does the porn director, Kelly, know that they are even filming a video so he can steal it? Assume he did and assume he knew that he knew Eli had it (which is another stretch I think) - the video tape he held up when confronting Matthew didn't have a label on it, so how'd he know which one to steal from Eli's house?
Corrected entry: The morning after the prom, a crisis breaks out when it is discovered that the tape has been stolen. Kelly has the tape, and threatens to play it for the parents and school official. When he does, it is fully edited, with complete titles. When the guys were making the tape they were using three cameras. It is highly unlikely that early the next morning this completed production would have existed at all, even if Kelly had somehow broken in unnoticed to steal the material.
Corrected entry: At one point the kid says he and the girl are the same age. How is that possible? He's probably 17 or 18, and since you have to be 18 to be in a porn movie, and since she's already retired, she would have to be several years older than 18.
Corrected entry: Towards the end, where Matt is in the changing room getting ready to star in the sex education film, he goes to walk out of the room, placing his hand on the door knob. After the shot of Matt, it goes back to a shot of his hand, which is in a different position on the door knob, to that of the previous shot.