That's not quite right - he left the camera out by accident. The monkey's taking photos was not his intention. If he had accidentally constructed a situation w

That's not quite right - he left the camera out by accident. The monkey's taking photos was not his intention. If he had accidentally constructed a situation where the monkey's pressing a button killed someone, we would consider it some kind of negligence or manslaughter (a much weaker claim) on his part, and the monkey would probably not be blamed. You're also assuming that the ability to be held liable for murder and the ability to hold copyright are satisfied by the same criteria.