There is a reason some folks are thought of as "safety nazis."
It is, quite simply, wrong and illegal to take the law into your own hands. Cut up my cord? Can you post bail? Don't I have the right to protect my property? Now, if a job super wants to order a piece of equipment removed- well, that's different.
Everybody thinks they're in charge. That is not the case. And there are too many "experts" out there whose holy crusade is inspired by that three hour seminar they attended last month.
Safety equipment- whether it be a hard hat or a GFI- is not intended to allow you to deliberately create a dangerous situation.
I doubt the plumber could do his job without ever getting electrical tools and water together from time to time. He should know this, and do what he can to protect himself. This means tools in good repair, GFI protection, making sure he's not grounded, etc. Still, doo-doo happens. To quote Frederick the Great: "Do you think you can live forever?"
I haven't seen a three-wire sawzall-type tool in decades. With a two-prong cord on the tool, the presence or absence of a ground pin on the extension cord is irrelevant.
