Other mistake: The toy store manager has his assistant gift wrap an empty box. The race car set is still on the table fully assembled.
Suggested correction: The manager brings the box to the counter and tells the assistant to gift wrap the box, but we don't actually see what happens in the store after Crisp leaves. There is no indication how much time has passed. It is plausible that the manager brought the box to the assistant and told them to gift wrap it, but that the assistant knows they will also have to disassemble the toy and put it in the box first. We don't ever see the car set still in the window after the customer leaves so we can't assume the assistant wrapped an empty box.