So your explanation is that all three women deliberately lied or deliberately withheld information. Why would they do that? Think women get off on being publically humiliated?
You answered your own question. It would have been humiliating to admit to affectionate behavour after the assaults, so they didn't talk about it. It was a pretty rational course of action, since it was unlikely that any other evidence existed. Unfortunately it did.
I'm not holding out the women to be particularly dishonest, we all behave this way at times. But in this case the consequence was an acquittal when there was a good chance of a conviction.