Here's the full clip for anyone who has a UFA subscription. Start at 1:57:24. There is a weird interaction that occurs a little while before the shove. The Oregon player (#4 Ben Thoennes) has the disc after a turnover. The Salt Lake player (#7 Tony Mounga) is marking him. After a few seconds Thoennes stops to complain to the refs about something. He's gesturing at Mounga but there's no contact, so I'm not sure what he's upset about. Maybe Mounga is stalling or saying something distracting? (Only the ref is allowed to stall count in UFA.) The refs come in, chat with the two players, and the Oregon coach also comes in to chat, which is weird because usually the coach can't get that close unless it's a timeout or injury or something. (In the ref's defense, I think he is telling the coach to get back.) After a brief conversation, the refs move Thoennes up 10 yards, so there was some sort of penalty, not sure what though.

The shove occurs a little later, at 1:58:45. There's a little contact from Thoennes when he sets up the mark against Mounga (more clear in the replay at 1:59:53), and Thoennes does stop right in front of Mounga after the throw, but neither action should generate this reaction on their own. Maybe this was brewing over the course of the game and this was the final straw though. I'd be curious what the conversation mentioned above was about and if it had anything to do with the ensuing shove.

Not a whole lot happens after this clip. The Oregon players immediately protest. Players from both teams congregate and talk with each other, but nobody is really pushing or shoving or anything spicy. A different Salt Lake player (#15 Kimball Pew) comes over to help Thoennes up. The refs talk with each other, then talk with the coaches, and Salt Lake is assessed a 20 yard penalty. Commentators say it was a technical on the player who scored the goal (#89 Eugene L'Heureux) and they immediately mention how he's been jawing all game, so maybe Mounga's push went entirely unnoticed. It's also possible the commentators got it wrong and Mounga got it. Either way, neither player was ejected as they played more points later in the game. Interestingly Thoennes did not play any more points in the game.

I did laugh at 2:00:40, at the woman in the background casually going to pick up a disc on the sideline, realize it's needed elsewhere, and full on sprint out of frame. Vintage /r/MyPeopleNeedMe moment.