Continuity mistake: When Alison is pointing the gun at Zep, Zep's position in relation to the bed changes instantly. (01:20:50)
Continuity mistake: When Adam takes the picture of Lawrence in the car park, the position of Lawrence's fingers on his face vary between the picture Adam took to the actual shot of him when he does so. (01:11:15)
Continuity mistake: During the quick montage of Adam and Lawrence cutting their chains, in one shot of Lawrence his feet are on white tiles and in others they are on broken sections that are black. (00:14:25)
Continuity mistake: When Adam and Gordon are talking in the beginning, Adam's hair moves between shots. (00:03:40)
Chosen answer: Yes. You pretty much guessed correctly. We can assume that Jigsaw told Zep to tell Ali to tell Dr Gordon, "do not believe Adam's lies..." Don't forget that Jigsaw spends hours planning his tests so it would be safe to say that he had planned it all in the beginning.