jlh, that guy's gonna' kill someone. He desperately needs a 'new assignment' as far away from you and your peers as possible, and likely some serious “administrative leave” without pay. It may be appropriate to question date and quantity of the guy’s OSHA-standards-based training and qualifications.
It may be time to independently contact your state's industrial safety/OSHA group. Spare no details during your interview{s}. If he doesn’t go away I would, and make it very clear my reasoning for doing so.
I would makes as many noted as possible about the incident, building on what you have written here if you need a place to start.
Er, fuses have no breaking or pickup current capacity when removed from or installed in energized fuseholders.
