Visible crew/equipment: When Sarah and Eddie return to the saturation chamber after losing the other two, the camera shot is high up looking down into the room from a corner. In the upper right hand corner above the saturation chamber you can see the microphone fully in frame and "hovering" as they re-enter that room. It is also there a second time after the camera angle changes.
House on Haunted Hill (1999)
1 visible crew/equipment mistake - chronological order
Directed by: William Malone
Starring: Famke Janssen, Geoffrey Rush, Taye Diggs, Peter Gallagher
Revealing mistake: When the house has been locked down at the beginning of the film no moonlight could come in, however when the guests are being shown the coffin with the guns in there is a shaft of bright moonlight shining on to it.
Evelyn: You know if you really love me, you'll find a way to drop dead in the next three seconds.
Stephen Price: Finding ways for me to die is really your deal, isn't it Eveline? Let's not forget the OJ knife with the not-quite-retractable blade. Your Jim Jones Kool-Aid was exactly that.
Evelyn: Accidents, all accidents until proven otherwise.
More trivia for House on Haunted Hill
More questions & answers from House on Haunted Hill
Answer: The Darkness thought he was lying to save himself, everyone killed had the seven deadly sins. Greed, Lust, Envy, Sloth, Gluttony, Wrath and Pride.