Major Plot Hole: According to the film scenario, Jigsaw was lying on the floor without motions for about 1.5 hours. However, the narrative stated that he was dying of cancer, so muscle spasms were possible during this time. Besides, he would have to breathe. Hadn’t this plot hole appeared near the end of the film, all the suspension would be completely destroyed. Such a serious plot hole made watching the second movie completely worthless.
Major Plot Hole: Gordon and Adam were hurt by electrical shocks via the binding chains. As far as the chains weren’t grounded, and were seated on the floor made of ceramic tiles, that wasn’t possible – the tiles would insulate electricity and prevent shock. At the same time, Jigsaw was lying in the middle of the wet floor, which means that any electric current going through the suffering men would affect the maniac, as well. It would at least cause some serious pain, but he didn’t even move or flinch when that occurred.
Major Plot Hole: The law enforcement representative claimed that Jigsaw couldn’t be charged with murder, because he didn’t kill anyone. That statement doesn’t correspond with the jurisdiction of the United States. In US, such a felony offense as what Jigsaw did (kidnapping and torturing in attempt to kill) is considered to be equal to first degree murder. In many states, several serious offences can serve as the foundation to charge a person with the first degree murder. A police officer should have known that and would never say such a thing.
Major Plot Hole: When the protagonists (Adam and the doctor) tried to cut the handcuffs and chains with the hacksaw, they realized that the restraints too hard. However, they didn’t pay attention to the narrow pipes: these could definitely be cut. Neither of them realized that before cutting off their legs.
Major Plot Hole: ANY cells phone must be able to call 911: this is the legal requirement in the USA. Otherwise, a mobile phone wouldn’t work properly.
Major Plot Hole: Jigsaw couldn’t have known that the cassette tape hidden in Adam’s pocket wouldn’t be damaged, while this item was crucial for his plan. However, he didn’t care about the cassette when Adam fell on the floor: had he landed incorrectly, the tape would have been destroyed.
Minor Plot Hole: When the cell phone calls, the doctor switches to a dial tone. However, usually cell phones don’t have dial tones unless specifically set up for that (though it wouldn’t serve the same purpose as a dial phone on usual phones).
Unaddressed Issue: While Dr. Gordon seems to be a deep-pocketed man, judging by his home and office with expensive furniture and decorations), he and his wife have only one vehicle, which is untypical.
