[Barrie Yates]

If someone is running flat out the slightest nudge on one of his legs, at a particular moment, can result in him falling. If the referee, and possibly the linesman, don't get a clear view of the nudge then the player is accused of diving.
Of course all the panel pundits will love the situation - they will get even more chance of telling us how a player cheated and should therefore be banned - and the bias from their playing days kicks in once again.