Guyver: Dark Hero (1994)

Revealing mistake: At the end of the final battle, when Sean rips the Guyver unit out of Crane's head and delivers his one-liner ("this model... has been recalled!"), you can see Sean's previously rigid, metal-like mask bending like rubber as his right shoulder rubs against it in the close-up. Particularly noticeable is the vent where steam sometimes shoots out, which bends nearly 45 degrees for about a half-second. (Revealing it's likely some sort of latex "stunt mask" for the actor to wear during fight scenes.)

TedStixon

Sean Barker: The Guyver Unit. It's been a year since the alien armor invaded my body and became a part of me. A year since I first became the Guyver and destroyed the Chronos Corporation and their shape changing killers, the Zoanoids. Now Chronos is gone. But the Guyver stays in me. Calling me to fight. To kill.

Trivia: Brian Simpson, who has three roles in this movie; Benny, Voker Zoanoid and Crane Zoanoid, also appeared in the first movie as a member of Craig's gang who attacks Sean.