10 Horror Movie “Mistakes” That Were Totally Intentional
2. Hoffman's Letter To Amanda - Saw IV
In Saw III, serial killer Jigsaw, aka John Kramer (Tobin Bell), tells his apprentice Amanda Young (Shawnee Smith) that there's an envelope with her name on it in his desk - an envelope containing a letter with evidently devastating news for Amanda.
In Saw IV's closing montage, it's revealed that the letter was actually written by Detective Hoffman (Costas Mandylor), yet in this scene we see Hoffman placing the envelope face down in Jigsaw's desk, despite Saw III making it clear that the letter was face-up when Amanda found it.
This slight error was pointed out by some fans, but was basically just an attempt by the filmmakers to keep the audience in suspense for a few seconds longer about who Jigsaw's new apprentice actually was, before the climactic montage revealed that Hoffman was indeed the new Jigsaw and had been blackmailing Amanda.