Revealing mistake: When the locksmith van stops at the mansion, the headlights have translucent covers taped to the grill. This was to prevent the lights from being too bright in the previous nighttime overhead shot.
Other mistake: When Martin Short accidentally fires a shot into the bank ceiling, he is holding the gun at an angle. However, plaster drops on him from directly overhead instead of from where the gun was aimed.
Continuity mistake: When Lucas visits Meg at the juvenile home, he carries a stuffed toy monkey by the leg. When the camera angle changes, he is holding the monkey by the neck. (01:08:15)