I have learned that when dealing with an angry student the best thing to do is listen to them first. I usually let them vent the entire problem off their chests, tell them to then take a deep breath, and go from there. I think it's important to keep your composure and try to be as diplomatic as possible. Finding the facts of the situation almost requires a Sherlock Holmes or CSI type personality but after you encounter this a few times it gets easier and easier.
