Honestly there is so much to talk about in this video I don't feel like typing all of it. It's a great discussion topic though and I would love to bring this up in the next meeting.
From the initial play referee should have blown the whistle for a foul and issued a red card to goal keeper reckless tackle. Then the insuing situations would have never occurred. It is very obvious that the referee didn't have control of this match. His AR's could have assisted also. Coach should have been issued a yellow card for coming on the field. Red card injection to #12 was correct but referee should have issue at minimum yellow to the player who shoved #12 immediately after the foul.
All of this could have been controlled with better game management earlier in the match.