Whenever travelling we always carry on anything we would need for overnight. It just is not possible for the carrier to go thru a whole airplanes luggage just to get your bag. The fact that they did dig out your bag is probably the reason the camera is gone - it was left in an unsecure area overnite. While getting delayed is never pleasant you should be prepared for it. And never check anything valuable. I sure don't like hoisting 50 pounds of chips into the overhead at convention time but I would never consider checking them.

If you travel there is another thing you should know. It is called rule 240. It basically says that if your carrier abandons you in the middle of a trip you can take your ticket to any other carrier and they will honor it. Of course at midnight that may not have helped you but keep it in mind for next time.