Stop in for a cup of coffee

Mechanic walking by another mechanics bench.

Transmission parts all neatly laid out on the bench for reassembly...

Mechanic looks around to see if anyone is looking

Takes a random bolt out of a box he's holding, and places it on the bench with the other bolts

Walks away smiling
You want evil, go to armors school, to pass you must assemble from parts a functioning rifle, then trouble shoot some devious created satan spawn malfunction. Example: take spring safety out, cutting off three turns and reinstalling cut side down. Instructors are evil genius.