its happened before. it's just an unfortunate defect his body has and would most likely have been unavoidable if he wasn't as fit or under pressure.
remember Kanu had a heart transplant, or something, then went on to found
http://www.kanuheartfoundationng.com/it happens randomly to people all the time, if unnoticed prior, and it's just that it happened at a high profile event that made it media worthy.
