I haven't tried that yet, as I don't mind them digging, just hate having to fill in the holes.
You and MATY are the only hacks I use anyway, Well, and InSim. I don't trust anyone else.
Also, that action has only happrned the one time so far. It was just after I put the hack in, and the action might have already been qued.
edit - Just ran the conflict checker and found a few potential conflicts, including your no stray visit and the visitor contoller from MATY, but nothing that I would think would cause that. Still, like I said, it isn't really an issue.