In a bowl game a few years ago, had a former Univ of Houston coach get mad at our chain crew because we stopped the game due to the chain coming off the stake. He said, "we want to go fast and you guys have to keep up." I turned around and told him "we can keep up if your coaches and players would stay out of the white and not step on the chains." He didn't say another word to us, but still didn't control his sideline, and for that matter neither did the flank official.
In this situation I would have reminded the coach that he should be behind the chains and said it loud enough for the flank official to hear it too. I would have run into him every chance I got the rest of the game when he was in the white.