Continuity mistake: In the ending to the previous film, Lynn gets shot in the stomach and falls backwards through the plastic doorway. In this version she falls forward into her husband's arms.
Suggested correction: Absolutely, positively incorrect. Not only does she get shot in the back and fall forward into her husband's arm in both movies, but they literally use the EXACT same shot of her falling forward into his arms in both films, so it's flat-out impossible for it to be any different. Need proof? Look up "Saw 3 - Game over, ENDING (Amanda, Jeff, Dr Lynn and John) " on YouTube and pause around 1:12. Then look up "Saw 4 - "Game over", ENDING (Eric, Blank, Rigg, Jeff, Strahm and Hoffman) " and pause around 3:36... it's the exact same shot in both films.
Factual error: It would not be possible for the scalping device to scalp Brenda's hair in the manner that it does. Hair is too thin to withstand that much pressure when being pulled and would rip long before she began to bleed profusely. At worst, she would likely be bleeding a little bit in a non-fatal manner from having her hair yanked after it ripped.
Suggested correction: Actually, people get scalped by having their hair get caught in machines with some frequency in real life. It's a troublingly real phenomenon. When the tension is distributed among all your hair, it can rip the skin clean off down to the muscle or bone.
