The Glimmer Man (1996)

Other mistake: When the killer and Segal are fighting in the last scene, and the killer is thrown out the window, you can clearly see the black shards on the window bend.

Jack Cole: You know, when you wake up in the morning and look in the mirror, I think you're probably happy. Pleased at what you see. And that disturbs me. So I'm gonna take it on as my responsibility to make sure that you never get to look in the mirror again.
Donald Cunningham: I woke up happy, I'm goin' to bed happy. 'Cause you're gonna be dead.

Trivia: Steven Seagal had some sort-of religious "breakthrough" before filming began and decided he didn't want to kill any villains in the movie. This caused some friction on the first day, when he was set to film a scene where he killed Stephen Tobolowsky. Tobolowsky, knowing how spiritual Seagal was, ended up convincing Seagal that killing his character was the right thing to do, as it would allow his character to be redeemed and reborn in a new body through reincarnation. The scene was filmed as it was scripted. Later, however, Tobolowsky got a call from the director, who informed him that Seagal kept improvising lines implying that Tobolowsky survived. Tobolowsky ended up having to come back out and record some wonky dialog of his character screaming "Finish me off!" to imply he survived and appease Seagal. In the end, the lines weren't used and Seagal's improvisations were simply cut out, so Tobolowsky is killed off as was originally planned.