2011 World Track and Field Championships
The world's fastest man shocked everybody by bolting out of the starting blocks just a bit too early. Usain Bolt was disqualified from the 100-meter final under a controversial false-start rule amended in 2010 by the IAAF. Previously, the first false start in a sprint would be a warning to the entire field and any subsequent false starts would result in DQs. Now, there are no warnings. All false starts are grounds for expulsion. Bolt actually false started in the semifinals of the 2009 world championships under the old rule, so he received a warning and stayed in the race.