I do remember the 2005 game well. The other example doesn't make clear who the fans were, but it'd be safe to assume that it was CSU fans since it was a field rushing scenario and they were the team that dominated and won.
I've got no love for CU fans and that 2005 'eject the entire student section' incident is hilarious and pathetic, but the NU fanbase's folklore about how monstrous the weed smoking hippies in Boulder are has always been silly and overblown and barely more than urban legend to me.