Continuity mistake: After Blart gets spray tanned, his shirt is a mess with the tanning spray. A few shots later, his shirt is white again. Then a few shots later, his shirt has got spray tan on it again.
Continuity mistake: When the bad guys are clearing the mall, the camera follows "Rudolph" as he clears an exit on his skateboard. As he starts to clear the exit a young man with a black jumper with a white top half can be seen on his feet moving away. In the next shot he is sitting down with a bag on a bench and then gets up to leave. (00:39:35)
Other mistake: When Paul is putting on the Hello Kitty bandaid, you can see the outline on his skin from another bandaid, from previous takes of this scene.
Continuity mistake: When Paul and the guy are fighting next to the air con intakes, the speed that the fan is spinning changes between the close and far shots.
Factual error: When Mya points out his Loch Ness tattoo, and asks when he got it, and he says the night before, it would not be healed as it is. It would still be red, raised, and be covered to protect it. Also, later in the movie when he is on the ground and we see the large tattoo across the whole back, this would also be impossible as a whole back tattoo would take at least two or three long sessions, and this movie takes place over just a couple of days.
Other mistake: The glass in elevators is tempered. It would not have shattered when the robbers pursuing Paul crashed into it.
Other mistake: When Blart and the SWAT guy are pursuing the bad guy, they have a blue police light on top of the car (the magnetic kind). Interior views of the car show blue flashes on their faces, which is impossible with the light being on the roof. The exterior shots confirm that the inside of the car is completely dark. (01:21:30)
Other mistake: In the beginning of the movie, Paul is at the NJ State Police training grounds. The training grounds, while near the ocean, do not have any islands just off the coast, nor is the ocean water nearby. The police cars used are painted light/metallic gray Massachusetts State Police colors with a blue stripe down the side. NJ State Police cars are white with red or red/blue lightbars with a blue & gold triangle logo on the front doors.
Continuity mistake: When Paul hides halfway in the air duct, his feet are hanging down when seen in the exterior shots. When seen from inside the duct, his feet are tucked up behind him.