What's alleged is irrelevant. The case was dropped because the standard for criminal law is "beyond all reasonable doubt", at least in any rational or sane justice system.
There is absolutely no way a case with this many holes in will ever - EVER - reach that standard of evidence unless they have something really unusual, like video evidence of what happened.
The chance of getting a conviction in this case given the weaknesses of the claims, the he said/she said nature, and the contradictory behaviour of the alleged victims afterwards (which included attempting to remove evidence that contradicted their story by deleting tweets etc), all point towards a failed prosecution. Hence, why Assange is suspicious.
