The main problem is the police reports.
According to the police reports, Michigan State first become aware of a sexual assault allegation against Nassar in May of 2014, when one of his female patients filed a Title IX complaint with the university.
That complaint led to two investigations: a Title IX investigation from the Michigan State Office of Inclusion and Intercultural Initiatives, and a criminal sexual conduct investigation from campus police. Nassar was suspended by the school during the Title IX investigation. However, he was allowed to return to work after it concluded and cleared him in July 2014, even though the police investigation was still ongoing.
From the documents, here is an email exchange from immediately after the Title IX investigation concluded—July 30, 2014. The correspondence is between Nassar and his boss, Dr. William Strampel,
who stepped down as dean of the College of Osteopathic Medicine last week