This one I have not tried in real life, but have been told.
The opposite team had put a marking on one of the players, a high shooting strong goal-eater. The coach asked the shooter to withdraw all the way to the sideline and place himselves in front of the opposite teams coach (a rather small person) in such a way that the shooter prevented the coach to see the game. He tried to follow the game by moving up and down the sideline, but the marked player did his job perfectly.
The matter could have been closed if the coach had dropped the marking or taken a position standing on the bench, but instead he choose to be irritated and at last he did the big mistake. He entered the court and pushed the player away. This was of course observed by the referee (who had followed the incident) and the penalty followed immediately.