How Dumb Can Someone Be?

I just have to ask the question. I returned home from work yesterday to discover the door to medicine chest in my bathroom open. That's the same medicine chest with Tylenol, Advil, prescription medicines containing codeine, bottles of rubbing alcohol, etc. A.k.a drugs and controlled substances. Thinking that it was my 3 year old son who climbed onto the side of the bathtub and opened it himself I asked my Au Pair to ensure that she keeps an eye on him when he goes upstairs by himself. She responded by telling me that it was she who left open the medicine cabinet. She added that she didn't think anything of it. WHAT????? She's a fucking moron.