These are the first six victims listed on the victim list: (1) Cecil Adams [Knife Chair], (2) Mark Wilson [Candle/Safe], (3) Seth Baxter [Pendulum], (4) Paul Leary [Razor Wire], (5) Amanda Young [Reverse Bear Trap], and (6) Donnie Greco [Question Mark Man in Reverse Bear Trap game]. One theory is that they could have found Cecil's body with the puzzle piece taken out, labeled the killer as the "Jigsaw Killer" and declared Cecil as the first victim. Amanda could have been tested before Mark and Paul but, since she didn't die, there was no puzzle piece cut from her. When she originally came forward about what happened to her, they couldn't have officially labeled her a Jigsaw victim, only assumed. Then they find Mark's body with the puzzle piece cutout. He is declared the second Jigsaw victim. But, the penlight couldn't have been there on this first discovery. They find Seth with the puzzle piece cutout and the same type of tape, with the puppet "Billy" explaining the rules that Amanda would have described to them and would have found at her scene. He is falsely declared the third Jigsaw victim. Paul is declared the fourth Jigsaw victim. Whether before or after discovering Paul's scene makes no difference; Hoffman might have gone back to Mark's scene and planted the penlight. With further investigation, because of the connection between the puzzle piece and the tape in Seth's trap, Amanda and Donnie are finally labeled the fifth and sixth Jigsaw victims.
The timeline would actually be like so: (1) Cecil is tested, dies, is discovered, and is declared the first Jigsaw victim; (2) Amanda is tested, survives, and goes to the police, but the perpetrator is unclear; (3) Mark is tested, dies, is discovered and declared the second Jigsaw victim; (4) Seth is tested, dies, is discovered, and is falsely declared the third Jigsaw victim; (5) Hoffman is captured by the real Jigsaw and is turned into an apprentice; (6) Paul is tested and dies; (7) Hoffman plants the penlight at Mark's scene; and (8) Paul's body is discovered, and he is declared the fourth Jigsaw victim. Through further investigation, links are found between Amanda's case and other Jigsaw victims. She and Donnie are finally declared the fifth and sixth Jigsaw victims.