The more I see and hear about this, the more I think Waters' firing was a CYA on O$U's part. BowTie let the stuff go on unchecked for years. Drake was put in a position of having to do something about it. Waters became the scapegoat. Some of the people interviewed during the investigation claim that what they said was only partially quoted in the report or was taken out of context. Many say that Waters was changing the environment there. Waters didn't get the nice parachute that Tressel got when he was ousted. If he's not hired back, Waters will sue, and it'll be ugly for O$U.
He could sue, but I see him losing badly. He got fired and he ain't coming back. OSU fired him because they don't want to headlines coming out that read "OSU facing Title IX lawsuit over alleged sexual harassment by band upper classman, condoned by band director" (a la
http://deadspin.com/tulsa-facing-title-ix-lawsuit-over-al...)
Many do say that he was changing the environment. I've also heard it said that he (1) called band members by their (sexually charged nicknames), (2) participated in the "underware only" practice, and (3) was present on band buses when underclass members were being "playfully stripped" by the rest of the band. At this point, he's probably still employable by a university marching band. I don't think he wants those sort of allegations vetted in court.