No, he didn't. The student was asked by CSO and the police to show his identification. He refused. The police were called to remove him from the Library. They had every right to take physical custody of him and remove him by force if he chose to remain non compliant.
I can tell you've never worked in law enforcement or the security field. When you have a non compliant and hostile subject, you don't open a debate with them. You don't stand around and argue with them. You remove them. If they choose to resist, you remove them in whatever way your department or company has deemed legal and appropriate.
Either you didn't read the article, or you are talking about a different incident. But the facts as we have them in the case being discussed here are; he was told to leave. He didn’t leave fast enough for the security guard who went and got two cops. When the cops got there he was on his way out like instructed by the guard. One cop grabbed him as he was leaving like the guard told him to do. From everything we know now, clearly, the cop assaulted the student.