thisbeme: You have PM to fencer. Its same as in OTB game when you call referee and in correspondence chess when you write to tournament director.

Of course, there is benefit. If you are trying to win you have more time to do it if defender wont claim the rule. In OTB game I claimed 3fold repetition in very bad position, so my opponents' chances to win were very good - but you are right, my chances to win were tiny:)