Other mistake: After the Leprechaun has used the small car with the pitchfork and rammed the pick up truck, it rolls down the hill 3 or 4 times. The leprechaun opens the door and all 4 characters are not in the vehicle. They have not only managed to all exit the vehicle and hide behind a boulder but have all managed to not receive so much as a single scratch and Jennifer Aniston's hair is still perfectly brushed.
Other mistake: When Benny signs the autograph for the fake baseball he signs it Babe Ruthe with an 'E' on the end. This can be seen when Smalls put it back in his step dad's trophy room.
Suggested correction: He did though it's apparently supposed to happen like that as one of the boys says "Baby Ruthe?" when he's signing it and a comment is made about how bad it looks. Strange as it seems; this appears to have been done purposefully for the movie thus would not be a mistake if that's what the actor was directed to do.
Other mistake: During the train chase Wallace steps onto the train track that's going to the left on-screen, then he goes to the right as if the train is going the opposite direction on the track.
Other mistake: Before the opening scene, where there is a paragraph setting up the history of the musical, in the third line there is a spelling error: "it's" should be "its" since it is a possessive pronoun and not a contraction.
Other mistake: When the fighter jet says he has a missile lock, the shot cuts to the screen. You hear the characteristic beeping of a missile lock, but the screen shows only open sky.