If you fine the team or the University, I could see LSU fans going to next year's game in Tuscaloosa, buying a cheap Bama t-shirt outside the stadium, going in to the game and throwing bottles on the field when a call goes against Bama. Tack on 15 yards for unsportsmanlike conduct. If the University of Alabama gets fined, so much the better.
What Vandy did was probably the best solution: put up a net.
High tech solution, place cameras on fans, hit rewind, zoom in, see who a perp was (young man, purple shirt, section 21, row 7, seat 7) , then direct police to escort the perp out of the stadium, and/or charge them disorderly conduct, littering, reckless endangerment, whatever fits.
Let that word get out and this silliness will stop forthwith.