Two good ones recently. Both playing NFHS rules.
1) R1, R2, one out. Laser to center field that was 50-50 chance for a catch. R2 takes off. R1 hesitates and reads (CF threw a guy out at second inning prior). BR is, honestly, the fastest kid I've ever seen. He rounds first and is ten feet towards second when CF one hops it and throws a little wide to home. At time of throw, BR and R1 are both in between first and second. Throw goes into deadball territory. I kill it and place the runners at second and third. Coach decides to argue we missed it because "you can't screw my runner for a good read. He would have had second on a clean hit. He should score." He didn't care about the rules explanation, so he found himself in the parking lot.
2). R1 one out, going on the pitch (hit and run). Batter smokes one to LF. R1 has touched second and is on his way to third. Catch made, runner is in trouble. He doesn't re-touch second, he just heads to first. Throw comes in, almost gets him, and ends up in dugout. Two base award puts him at third, and thus touches second on the way. Coach insists they can appeal the missed base still once we start back up. I put the ball in play normally anticipating this improper appeal. I point and say "play." Coach says, "ok, throw to first for the appeal." Clearly the wrong base. The pitcher, a lefty, realizes this mid-move, and first fakes a throw to first then turns and throws to second. So now we have a balk and a run. Coach doesn't even bother to come out. I just smiled to myself under my mask.