Interesting thing to speak about. Should the referee be involved in how communication goes between the coach and the players? Most often than not, you will not intervene as it is strictly tactical or encouragement issues. But if the coach crosses the line?
Case in point, this past weekend on a field by mine while I am at halftime in my match. Game is evidently tight by all the yelling and screaming from both team parents and benches, etc. Ball goes to white attacking on the left side, so totally the referee's quadrant. White player goes down after a challenge. Referee calls the foul and the blue coach gives an earful to his player, sounding somewhat hostile. Referee does not interact in this case. I did not see hear anything too terrible but I was too far away to hear everything, but the blue player did not really take kindly to whatever was said.
2-3 minutes later, same white player and blue player running down the sideline again and the white player goes down again. Referee does not call a foul in this case, and the white player is down clutching his head. Blue coach is right beside the play and yells out, "Get up you pussy. Where did you learn to dive like that, the EPL?" He goes on to talk some more to the white player not as loud. The white player eventually gets up and when play stops, the referee checks on the player and he gestures to the blue coach. I inferred something like "Are you going to deal with this?". Nothing was actually done it seems, as the referee does the universal "enough" crossing of the arms, but I was kind of appalled of the interaction.
My thought is that you talk to your players much more than what you can talk to the other team's players. And there is still a line that cannot be crossed. I probably would have addressed it had he said that to his own player, but to the other team? I would certainly have addressed it with him. To me that was unacceptable. Especially with what was said. Again, to his own team, in a non-public manner, I probably would have let it slide but publicly, I would have said something and to the other team's players, I certainly would have said something. Again, my feelings here, but would like to hear what you think about player/coach interactions like this.