The Hermits and Vault hunters alike, people who actually KNOW Iskall, considered him a friend and co-worker, and interacted with him on a regular basis, have confirmed that they HAVE been given sufficient evidence beyond what has been made available to the general public (which, given the intimate nature of the accusations, is understandable).  Not a single one of them has come forward to claim that there's any gray area or room for doubt in what has been shared.  That in and of itself IS fairly damning evidence.