Had an easy one yesterday morning in a middle school game. A1 dribbles across half court into a trap by B1 and B2. Picks up his dribble, and they close in like sharks smelling blood. He gets frustrated and starts swingin his elbows.
Tweet! I call the violation before one of those flying elbows lands in a restricted zone or something. We're heading the other way, and coach A wants to know what the call is (as if I hadn't announced it.) Told him, and he looks at me and say, "How's he supposed to protect the ball, then?"
While I thought about saying, "by not dribbling into a trap," I just said "not by swinging his elbows."

I had my first one at the very beginning of the season. The team's coach who the violation was called against said: "don't you have to make contact", he was asking in a nice way, I said yes, if you want a foul on that player. I explained it from there and everything went fine from there on out.

I don't think this coach really knows the rule that well; kind of like yours. The court had a restraining line, and we whistled one of his players for a throw-in violation when a teammate of the thrower was outside the restaining line. Sideline throwin, and teammate was about 30 feet from the thrower but completely outside the restraining line.
This was the home team. Coach thought it was a warning the first time, so I had to take a moment to explain to him that it's a violation on the offense, and a warning on the defense followed by a technical foul on the defense for future offenses. We ended up calling about 4 violations and one delay of game warning in that game for that.

That's one thing that suprises me about the restaining line. In the schools that have them, probably 9/10 times, at least from my experience, the violation is on the home team. I just don't get it! :)