It's all down to the enlightenment and modernity.
Did you see the poor fucker who ran around half the stadium celebrating his bronze only to be told he had been disqualified. Ouch.
that Kenyan woman who got silver in the Marathon didn't know there was someone up the road in gold until that lap thing they ran outside the stadium.
She was sat in the group, thinking she could take them all in a sprint, and with less than a K to go there's suddenly someone 500m ahead of her.
Bollix.
edit, that sort of thign used to happen all the time in cycling, before every rider had a little intercom thing. 8 lads would break, 4 would be caught, and then 3 would be caught, and the pack would think they have them all back, and then there's a massive sprint, and they're told the race was already won.
A mate of mine won a race that way. No one realised he was gone.