It's a master-tier Darwin Award win. That's why it's funny. Same reason should-have-known-better accidents often get a laugh even when the consequences were pretty grave.

"I'm a highly-trained scientist who helped develop the bombs that leveled two cities and usher in the nuclear era... yeah, lemme just fuck around with this bomb core and a screwdriver such that I'm one muscle-twitch from killing everyone around me, that seems fine."