iPod Nano sets man's pants on fire in airport

This sounds kind of dubious but apparently an Atlanta man named Danny Williams was walking in an airport and his iPod Nano started to flame up. A “glossy piece of paper” protected him from life-threatening burns. Apple is being good sports about it and is offering him a new iPod after Willams went to the local news station with the story. The reporter got no quote from Apple, probably because it never happened.

My question is this: I know laptop batteries hold a lot of juice, but this is an iPod Nano. What specifically can discharge that fast and that powerfully that it could cause the case to overheat and burn, even in that small space. Is this even possible, electrical engineers?

Man’s Pants Catch Fire At Airport [WSBTV]