At the point where the prosecution or the judge thought the witnesses were lying, the case would have been ended. There have been instances where an accusation has resulted in prosecution, but they would tend not to reach the stage of a jury deciding.If people have knowingly lied to frame someone & in a court of law, how about they face prosecution.
What has happened here, is that the jury listened to all the evidence, and decided that there was reasonable doubt about whether he committed the crimes. Being found not guilty doesn't mean they decided that he was innocent, or that the women were lying, or that he did nothing wrong. Legally all it means it that they weren't 100% sure.
The prosecution has to prove the rape, and in cases where it's one person's word against another, then it's an incredibly high bar. That's a major reason why rape is an incredibly difficult crime to prosecute.
I didn't sit in court and listen to all the evidence in this case, and wouldn't presume to comment on whether the verdict was correct - but I will say that the verdict categorically does not mean the women in this case lied and tried to frame him.