Anyway I wasn't unduly bothered by it, although we resolved to find out where egress had been made and fix up the fence at that point. We'd told our neighbour of the situation and he said he'd round them up and drop them off in a few days when he had the time. It wasn't really a worry as we get on well with our neighbour, and he knows our sheep, there was no danger of anything bad happening to them. We could even see the silly pair over the fence any time.