[Andy]

I would say that you should not have intervened until the coach was restricted to the dugout by your partner. Once this happened, your partner has declared that s/he is done with the coach and is no longer going to talk to her.

Get out to the coach and let your partner get away from her. Your actions at this point should be nothing more than..."Coach, you have been restricted, please return to your dugout" No discussion about the play or your partner or anything else. If she refuses, then eject. Now she has to leave sight and sound.

If I turned around and saw her at the scorers table directly behind the backstop, this game is over and I'm leaving.

I agree with your decision to give her a lot of rope since she was the only coach, but at some point, that rope runs out and her and her team needs to deal with the consequences. For me, the end of the rope is the ejection.