How about this How about a way of letting the ref know it was an accident. For instance, last night taufua grounds it unintentionally so when he gets up say for instance he pats his head twice to play on. If he does this he has then taken advantage and say he gets dragged back in goal, bad luck for him, he took advantage. This way the attacking team is not getting screwed for slipping over when the defence is 30m away. It could be a pat on the head, quick tap on the foot at the tryline, anything to let the ref know you wish to play on.