The sexual assault accusations by dozens of women against comedian Bill Cosby, if true, would mean he’s a serial rapist. But the trial that began yesterday is about only one incident involving one woman. Since it’s too late to file charges in the others, Americans appalled by Cosby’s alleged pattern of sexual predation have pinned their hopes on his present accuser, Andrea Constand. They should probably get ready for disappointment, because new information shows her post-incident behavior to be so un-victimlike that she is simply not credible.

In January 2004, Andrea Constand visited Cosby’s home, where she says he gave her pills to relax, then sexually assaulted her. After that night, Constand kept mum about the incident until a year later, when she says had a “flashback” and told her mother what happened. Next, she reported her experience to the police, who investigated but dropped the case. In 2006, she settled a civil lawsuit with Cosby.

Cosby, who has pleaded not guilty, could face up to 30 years in prison if convicted. Even if that didn’t represent a likely life sentence for the 79-year-old entertainer, justice requires he be judged only by the facts in this case. Since only two people were in the room and there is no physical evidence, Constand’s credibility is the crux of the case. And the jury must acquit Cosby if they believe her story only a little more than his. They can convict only if the prosecutors convince them that her testimony demonstrates beyond a reasonable doubt that Cosby is guilty of sexual assault.

That’s going to be hard for them to do. Here is some of the post-incident evidence that cast reasonable doubts on Constand’s story:

When Constand initially filed her complaint in 2005, she denied any contact with Cosby since the day of the incident. We now know of 72 post-encounter phone calls, including 53 originated by Constand. Some lasted more than 30 minutes. Why would a woman who suffered a horrible trauma that justifies imprisoning a man take his phone calls, and initiate many more? Surely she’s not claiming the drug she took continued to leave her powerless during six dozen follow-up chats.

And why did she lie to investigators about those calls? Seventy-two is just too many to expect jurors to believe they slipped her mind. Surely she knew acknowledging the calls would undermine the case against Cosby. The defense will probably suggest her motive for the deception was related to her planned civil suit, but she may have simply been angry with Cosby (for whatever reason) and wanted him punished.

Her strange post-incident behavior goes further. In the summer of 2004, she attended one of his comedy shows with her parents and brought him a sweater as a gift. Surely this is the first time in history in which a woman hopes the man who supposedly assaulted her will make her laugh for a half-hour or more.

Her claim she kept silent because she didn’t remember the incident until a “flashback” triggered her memory will be very hard for jurors to believe. That’s because Constand has given other reasons for her year-long silence, including fear of losing her job in the Temple University athletics department. But she had left that job by the time she moved back to Canada in April 2004. Is she suggesting she remembered her attack for the first several months, then forgot about it, then remembered it again in a flashback several months later? To me, that’s reasonable doubt right there.

She has had fuzzy memories on other details, too. For example, she first claimed the incident took place in March, a month before she left the country. But later she said it was January. That’s not like forgetting if it was Tuesday or Wednesday. Jurors will have to decide if they believe the totality of a highly charged accusation by a woman whose memories appear to shift in the wind.

The most frustrating part of the weakness of this case is that Cosby sure seems to be guilty of something. After all, his 1969 comedy album included a routine called “Spanish Fly” in which he boasted (um, comically) of trying to obtain a drug that would make women want to have sex with him. In a civil deposition in 2005, he admitted having purchased Quaaludes for the purpose of doing just that.

And, of course, there are all those accusers. More than 50 women have come forward in the past few years alleging Cosby assaulted them, often using drugs, sometimes with details very similar to Constand’s. But none of those cases can lead to criminal charges because of expired statutes of limitations. Constand’s was the only case that could still possibly be tried, but time was running so short that the charges filed on December 30, 2015 came just two days before the legal window to do so would have closed.

That timeline sure appears to support the idea that Cosby is on trial not for the encounter with Constand but for all of his alleged misdeeds. That’s not how our system works. His proceeding must focus narrowly on whether there’s reasonable doubt he assaulted Constand. If indeed he’s a serial rapist, his continued freedom would be a terrible injustice. But if he’s not guilty in this case, imprisoning him would be, too.

David Benkof is a columnist for The Daily Caller. Follow him on Twitter (@DavidBenkof) and Muckrack.com/DavidBenkof, or E-mail him at DavidBenkof@gmail.com.