Question

Three complainants, men and women, have publicly accused a certain rabbi of sexually abusing them in their childhood. All three can describe the abuse in detail — where it happened, how it happened, and so on.
The rabbi and his supporters claim that the complainants are all mentally ill, and there is some substance to that claim. Beyond that, since all the incidents supposedly happened in the past and behind closed doors, there is no way to verify them other than the complainants’ testimony.
Still, even if we assume that all three complainants are mentally ill, it does not seem likely that all of them would just happen to imagine that this specific rabbi raped them rather than other rabbis, which is not something that generally happens.
Based on this testimony alone, is it correct from a public and religious standpoint to relate to that rabbi as a rapist? Is there any plausible explanation for the complaints other than that such a rape really took place?