A while back, working a D-3 game as Lines Judge, a fight started near the opposite sideline, I turned, faced my team, signalling stop. Several players moved past me and (I made the mistake of following my instincts) reached out and grabbed a passing arm. That arm felt like a steel light post, and a (very large) player, with youthful fire in his eyes, spun around, saw who I was and immediately replied, "Sorry Sir" and went back to his sideline.
I thought, "WOW", how lucky I was that the player I grabbed was raised by good parents and was brought up right to respect authority, and how big a wolf I was holding by the ears, for that split second. That "instinct" was immediately tossed in the garbage and replaced with the instruction to reach for my game card and note the numbers of anyone else who left the sideline, which has served me far better since.