Revealing mistake: During the Turtles fight with Shredder watch carefully, the blade on his left hand bend back, made of rubber.
Teenage Mutant Ninja Turtles (1990)
21 revealing mistakes - chronological order
Directed by: Steve Barron
Starring: Sam Rockwell, Elias Koteas, Judith Hoag, Josh Pais, Michelan Sisti, David Forman
Revealing mistake: When three of the turtles are playing Trivial Pursuit and Leonardo runs in to announce Splinter is alive, you can see a wire coming out of Raphael's shell. I guess it's for the animatronic head, but it's visible. (00:59:30)
Tatsu: Go... play.
More trivia for Teenage Mutant Ninja TurtlesMore questions & answers from Teenage Mutant Ninja Turtles
Answer: Most likely to kill Shredder and make sure that there would be no way to come back but, as seen in the sequel, Shredder does return.