In a perfect world (own perspective), stopped on line(briefly conferring with co judge), explained to handler excused (99% would know why). Then giving handler the option to pick up the birds-- pretty cut and dry. Waiting for call backs would not be so good. I have seen both scenarios, as well as handler and judge. It happens, as does interference: throwers, gallery, training, train, loose dog and misc.. When it gets grey, one could rerun and or slide by given the stake.