You obviously haven’t been paying attention. Title IX compliance within the USU football team has been a train wreck for years. This is not an isolated incident in regards to a culture of compliance within the team. And when it comes to Higher Ed, even the smallest failure (like choosing to tell your AD rather than the Title IX office) of following Title IX policy is fireable. Also there is no downside to reporting in this situation as if the girlfriend maintained the statement she gave to Anderson they would have had no grounds to punish the player.
Title IX is treated in higher ed like corporations would treat anyone violating federal finance laws. Even the smallest clerical error could have you out the door.