Revealing mistake: After the guy gets killed in the alley, he lifts his arm to allow the other guy to drag him away.
Continuity mistake: Tom and Finn bury a rope in the sand after tying it to the lifeguard stand but the next day they pull up a chain instead.
Continuity mistake: Kari and Traci are both wearing sandals barefooted when they are caught toilet papering the house by Tom and Finn but when the four of them go for a walk on the beach minutes later, Kari is now wearing grey sneakers and Traci has black socks with her sandals.