Visible crew/equipment: Just as we see the flashback with Amanda, Jill looks at where Amanda stood, then turns to where John was stood and sighs. As she does, a boom shadow is seen to move across her hair. (00:23:15)
Visible crew/equipment: When Jigsaw says to William, that "success lies in the failure of your adversary", a boom mic can be seen reflected in the TV screen. (00:27:50)
Answer: The tools were chained to the tables, and there wasn't anything else they could've thrown down onto the scales.
erikvduyn