During the campfire scene, Mike Strauber is dared to rip out his tongue. Later, he is able to talk frequently. This is explained in the film as being through speech therapy, however, this would not help a man lacking a tongue.
During the escape from Sunnydale Mental Institute, several obvious stunt doubles for Mike Strauber are used, including noticeably dissimilar hair styles and wardrobe.
During the Sunnydale Mental Institute scene in which Mike hallucinates two old men, he instructs one to cut off his arm. He only cuts off his hand. Later, Mike incorrectly reprimands the same man, telling him he had requested for his leg to be cut off. Mike Strauber never told the old man to cut off his leg.
During most of the film, but especially the end scene where Mike Strauber is shot, his "copper" mask appears to move with his breaths, indicating its true rubber state.
When the Warty Man's head explodes in the hospital, duct tape can be seen on the wall in the background while flesh is falling.
During Mike's escape from the asylum, Mike kicks a man in the face before stealing the man's car. The kick to the face is extremely fake looking as he obviously doesn't even come near the man's face.
During the drive to the camp site, while Mike Strauber is disturbed by his memories, there is a frame of a later scene in which he is getting supplies for the camp site from the location.
During one of Mike Strauber's many flashbacks, there is a scene in which he and his wife are sitting by the pool and his wife asks, "Is it that hard to believe it could get a little boring around here?" but the audio cuts out before she finishes the word "here." Later, an audio flashback uses the same clipped segment.
Starting within the very first ten minutes of the film, Mike Strauber has the unique and uncanny ability to generate weapons from thin air, such as the pistol he grips when contemplating suicide. Director Tim Ritter explains in the commentary that there were missing scenes in which Mike Strauber goes to a hardware store to get "supplies," however most of the weapons Strauber generates cannot be found at a hardware store.