The serial number of the lost Pearbook changes several times between "712581 624 297-A" and "712581 629 297-A".
When Spencer tries to play in the arcade to win his prize. The employee tells him he's not allowed in the game room unless he's with a kid. The rule is ridiculous because in real life. Arcades have no age limits in real life.
Guppy was wearing a watch but when Spencer asks him what's the time. Guppy checks the time on his phone.