Shane;
It is my opinion that saying "watch it" is not the correct call. If you need to say "watch it" you just gave that kid a free cheap shot.
By calling them for unnecessary roughness and awarding their opponent a penalty point, it sends a message to everyone in the gym that you will not tolerate that stuff on YOUR mat.
Are you going to say "watch it" to the opponent when he takes his cheap shot? Because you know if given the opportunity, they are going to 'get even'!!
Wrestling is a very tough sport to 'Ref' for sure and wrestling is a tough sport done by tough people for sure but I think you guys need to step in more, at the high school level, and stop some of the BS that goes on.