That's not entirely accurate. Much about the police isn't true. The police did not reveal that Paul did not rape her, or that she was stalking him. I'll go through what happened:
First, Emma Sulkowicz (the "Mattress Girl") did claim her "friend with benefits" Paul had anally raped her during otherwise consensual sex and didn't stop when she asked him to.
She filed a complaint against him with Columbia many months later. The police reviewed the evidence and didn't find any evidence to back up the claim. They "cleared him" in the sense that there wasn't even sufficient evidence to charge him, not that he was innocent.
Columbia university held a review of the complaint, one where he was not allowed to defend himself, and the conditions of finding guilt are only "preponderance of the evidence" (as in civil trials) rather than "beyond a reasonable doubt" (as in criminal trials). Note that the punishment for being found "guilty" in the university system ranges from administrative restrictions on campus to being kicked out of the university. That is, it isn't a criminal trial but rather evaluating if you've violated the "code of conduct".
In that review, Columbia found there was insufficient evidence to even meet the "preponderance of the evidence" claim, meaning there wasn't enough evidence to suggest it was more likely than not.
Emma was not happy about that. As part of her arts degree, she needed an art project. She requested from her project supervisor that she be allowed to carry around "the mattress she was raped on" as her project, called "Carry the Weight" to symbolize the burden that she has to carry by being raped, him getting no punishment, and Columbia not helping to get rid of him. The prof approved and Columbia officially helped, providing vehicles, space, and other aid in her project.
She became famous and celebrated for it and was even invited by a U.S. Senator to attend Obama's State of the Nation address.
Paul kept quiet. Under the rules of the review, neither Emma nor Paul were allowed to discuss the case. The problem was, Emma was not abiding by that and only her side was being heard.
So he sued. Not her. He is suing Columbia for supporting her to harass and bully him, and pressure him to leave. Her project (and publicity) revealed exactly who he was and what he was accused of. His life at Columbia was hell and job prospects not great given what comes up when Googling his name. Columbia did nothing to stop Emma from discussing the case she wasn't allowed to discuss. They supporter her in her project that portrayed him as a rapist even though Columbia found him not guilty. They supported Emma in her harassment of him, a violation of Title IX discrimination. And they let her (or at least did very little to stop her) carry the mattress on stage at graduation last week.
As to the evidence. Once Paul sued and could now speak up, he released much of his evidence of facebook messages, texts, and emails. Before and after the date in question, Emma was all over him. She even asked him to "fuck me in the butt" in a text. She showed no signs of evenly mildly disliking him anywhere after that did, and was telling him that she missed him a lot and they weren't seeing enough of each other. (They weren't dating; but had grown from friends with other gf/bf to "friends with benefits" a few times.) The messages were more consistent with a classic case of her wanting a deeper relationship and him growing distant because he wasn't interested but didn't want to break her heart.
A sideshow to the story is that one of the resident coordinators at his co-ed dorm appears to have had a vendetta against him, coordinated with Emma. First, Emma convinced Paul's ex-girlfriend to final a complaint against him, which she did. It was baseless and Columbia found for Paul. (For context, when Paul was dating his ex, he had talked to Emma at length as friends about the problems they'd been having.)
The resident coordinator believed Emma and tried to get Paul kicked out right away. When that didn't work, she filed against Paul herself, saying he tried to touch her at a party or something like that. Columbia found for Paul. She convinced another student to file against him, who claimed he had tried to kiss her at a party. Again, Columbia found for Paul.
Finally, recently, a former male friend of Paul's filed against Paul for trying to touch him sexually after they'd had an argument. The argument was about Paul's girlfriend at the time (the same ex in question), and the male friend had told her everything about their conversation, which annoyed Paul. Again, texts and messages all supported Paul and not the complainant, so Columbia yet again found for Paul.
So now there's his lawsuit left.
What the evidence appears to suggest is that Emma was upset at Paul for pushing her away when she grew feelings for him, that his former male friend turned on him to be closer to Paul's ex, and along with the convinced res coordinator they attempted to bully and harass him. At least that is his claim and all of the evidence so far, from all sources, supports him and none of them.
Columbia has at least found him not guilty in all of the filed complaints, but as his lawsuit suggests, they have done nothing to stop the group from using Columbia processes to harass and bully him, including Emma's project, and have even supported such harassment.
Supporters of Emma, like the OP video woman, claim that the messages just show Emma handled the rape in a "different" way. The first problem with that claim is that there is a significant amount of evidence here and all of it consistent with Paul's story and not hers. (Witnesses even describe seeing no change in her behaviour whatsoever around the alleged rape time, including not even walking funny the next day, which would be the case had things happened the way she claimed.)
A second problem with this type of claim is that it becomes indistinguishable between somebody who wasn't raped and somebody who was raped but is acting as if they handed been (and is a damn good actress). If those two cases are indistinguishable, then there can't possibly ever be evidence of guilt. Such claims become moot then. There is no conceivable system of justice that could ever achieve justice if the evidence for innocence and guilt look absolutely identical. By definition, it just becomes a coin toss at that point. And, since justice requires a presumption of innocent until proven guilty, such a claim equates to saying that any true justice system must find them not guilty in such cases.
Really, such claims work against the idea of raped women getting justice. It basically defines it as being impossible. Thankfully it is a generally baseless assertion. Raped women do show signs of it that are different. They may not always be signs we might expect, but they are certainly changes in behaviour. Emma just had none.