Deliberate mistake: During the sting attempt towards the beginning, Douglas confronts Snyder on the roof of the building. A helicopter rises up from nowhere without making any sound prior to that.
3 Ninjas (1992)
1 deliberate mistake
Directed by: Jon Turteltaub
Starring: Victor Wong, Max Elliott Slade, Chad Power, Michael Treanor
Other mistake: When the three ninjas are kidnapped and locked in that room, Tum-Tum is complaining about being hungry. Later on, before the fighting match between Grandpa and Snider, Tum-Tum gives Grandpa jelly beans. Why didn't Tum-Tum just eat those before?
Fester: Hey dude, what time does school get out?
Hammer: I don't know. I never stayed to the end.