Trivia: When Jigsaw and Eric escape the lair via a hidden elevator, the film's low budget prevented the construction of an actual working elevator. Thus, some trick photography and editing was implemented. For the first shot of Jigsaw and Eric "going down", the scene was shot by raising the camera vertically to give the impression they were descending. For the next wide shot, simple digital effects were added to make it appear that the room was "lowering." And for the final shot where we see the top of the elevator going down an elevator shaft, stock footage from the film "Hollow Man" was used.
Trivia: In Jigsaws lair, where he was caught, you can see items around the room from the house in which the 8 victims were being held. You can see the oar Amanda picks up from the basement and the X marks the spot photograph. These are clues to show that the camera footage is recorded. This is confirmed on the DVD commentary.