Speaking of horrible casting, Hoffman does not live up to the title of Jigsaw’s apprentice and is simply not a compelling replacement. Through there is some debate as to whether the traps of Saw IV are masterminded by Jigsaw (the film runs concurrently with Saw III which can give the viewer a serious case of vertigo) I tend to think that the traps of Saw IV are Hoffman’s because they do not fit Jigsaw’s “hurt to heal” mentality.
The straw that breaks Saw IV’s back is the ending. Saw IV tried to replicate the narrative pattern of Saw III, with a central character facing trails in order to let go of an unhealthy obsession. While the twist of Saw III left plenty of jaws hanging agape, Saw IV presents a twist that’s obvious from the start. The only way for Rigg to save Detective Matthews is to let go, and it’s his stubborn persistence that leads to the other man's death. As the music swells and the “reveal” unfolded all I could think was: "Don’t pull crap out of hat and tell me it’s a rabbit."
Up Next: Saw V