From the New York Times:

Less attention was paid three months later when a law firm hired by Smith College to investigate the episode found no persuasive evidence of bias. Ms. Kanoute was determined to have eaten in a deserted dorm that had been closed for the summer; the janitor had been encouraged to notify security if he saw unauthorized people there. The officer, like all campus police, was unarmed.

And...

But they did not offer any public apology or amends to the workers whose lives were gravely disrupted by the student’s accusation.

Basically, the so-called "student" outright lied about what happened and fabricated a tale of racial grievance.

She should be expelled.