Yeah, if the filament is loose that should be your first step, it may not be able to keep the switch closed consistently.

Make sure both ends of the cable are seated firmly.

Open the sensor up and check for any debris that may interfere with the microswitch.

If both of those are ok, you'll want to check continuity of the cable with a multimeter, to make sure the cable hasn't broken internally somewhere. Once that's confirmed good, tape the switch closed and test continuity through the switch. Typically those sensors are made with really cheap microswitches, so you may need to just swap it out with a more reliable switch.

Good news is they're extremely simple, and so pretty easy to test.

There's no stock or similar security, so the SEC doesn't care at all. Could be a plausible deniability thing, I just think it's more likely that he really is that dumb, given the stories about Tesla/SpaceX having teams that basically existed just to control him.

There's no stock to tank. You could argue that he's trying to tank the company, but there are easier ways to do that.