Other mistake: There is a scene where the gang is the home of the Bank President, just after dropping off the injured bank guard. At one point the Bank President is standing behind an end table of some kind with a lamp on it. Even though there is nothing underneath the table to block your view you cannot see the lower part of the Bank President's leg. It looks like it has been cut off.
Continuity mistake: After the gang's encounter with the hermit they head back to the Mystery Machine, and when Fred opens the passenger door in the wideshot its colors are the usual blue, green, and orange, but in the closeups the door's exterior is solid green. The style of the door handle is also different in the closeups.