Just been thinking about his story and something else has occurred to me.
He told SH that he was using the circular saw to cut the toilet pipe or pipes. But she went shopping with him for all the cleaning supplies and so on - and nowhere is it listed that they purchased any toilet pipes or plumbing supplies at all. So how could she have believed that he was sawing/fixing the toilet using a saw, when all he could have cut up would have been the existing toilet, which obviously didn't have anything missing from it, or any damage to it.