Stupidity: A detective who explicitly frequents morgues not being able to tell the difference between a real slashed throat and fake blood spurted on a neck is one thing. When he returns to the room and finds the body missing, instead of becoming alert, drawing his gun, putting his head on a swivel, and warning his friend outside, he slowly walks over to examine the razor and figure out how the magic trick was performed, allowing the killer to ambush and kill him almost comically easily.