Stupidity: When Michael goes to Judith's room, all she says is, "Michael, what are you doing in here?" She doesn't even ask why he's all bloody.
Suggested correction: It's Halloween, and she most likely thinks he's got into the spirit. Let's also not forget how she treated him earlier when she blew off taking him trick or treating. It's obvious she doesn't care about him at all and is beyond self centered so it's not surprising she wouldn't comment on it.
Stupidity: Mason should have also removed the other gun he had in his office for display, or he could have removed the bullets from the guns. There is no reason he would have to use these guns for his victims, so it makes no sense to leave the other gun in his office or have them loaded with bullets.
