Before you criticize another teams emotional reaction after winning a game that practically no one gave them a chance to win, you should try to put yourselves in their place. Also, why don't you check with your athletic trainer and ask them what the Riverside players were saying about a certain Eastside player before the game. Things like " She's been hurt and hasn't played all year, so she probably sucks!" How do I know this? Because your trainer had the class to check on this players emotional state when she knew that this player had overheard these comments prior to the game when she came to get some Advil. Just because it was done privately, doesn't make it any less unsportsmanlike.
Both teams played extremely hard and sometimes when you are 15 -18 years of age, your emotions can get the better of you.
I think last year when Riverside upset Eastside in similar circumstances @ Eastside, no one complained about the Riverside celebration that occurred after the game.