In a college club game I was involved in a similar situation. One team was undefeated coming into the game. The game was tied at 86 minutes with 5 yellows. I was AR and the ref called a PK, which gave the undefeated team a win to continue their streak. The losers were over the top with anger at losing and blamed the ref crew. After the end of the game we had to issue a red for OFFINABUS. The emotion is a tricky thing to manage, especially with adult players. The foul is usually a product of frustration and lack of control. The PK call exacerbates the emotion. After making the call to back toward the goal line is one obvious move. What other techniques have you all used to manage these kinds of situations?