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.
Continuity mistake: When the zombie Barry falls on Jordan, he's played by an obvious stunt double who isn't wearing any zombie make-up.
Plot hole: Georges repeatedly tells immigration officers about his Africa trips. This overlooks that fact that INS would have or request a copy of his passport to process his case. In real life, INS would have realised immediately that the Africa story was not real: no entry/departure stamps in his passport.
Other mistake: Tough beat cop Farley Wood in his spare time built a special electronic machine to feed his cat. He needs to take off for Miami at 3 PM. When his cat is eating before his departure though, the clock on the machine says it's "12 AM", which would be midnight, not noon.
Other mistake: The hole that the guy got his arm torn off in was too small to fit into, despite the monster being on the other side. A few moments later, he's pulled in. If the opening was too small, the body would be crushed and blood would spray everywhere, but you see none.
Other mistake: When the coroner lifts the sheet to show the cops Jimmy Kong's body and shows them the dim mak bruise on his chest, you can see Jimmy breathing.
Continuity mistake: The leather straps on Charley's legs on her bed keep loosening up between shots.