If so, then one would only need to demonstrate a sufficiently impressive failure of current scientific understanding to account for some events that would appear to be caused by his actions, in order to push what would be considered a plausible religion.
I might be mistaken about the use of the word "plausible", but I think it is not necessarily connected with evidence but with human perception. Of course rational people would only find plausible explanations that are backed with evidence, but even the most hardcore rationalists are subject to their own psychology and emotions.
My argument is that in a (completely unlike, hypothetical) scenario like the one I describe, most people would likely find plausible what that someone would claim (if it did not sound completely stupid) not because it would be the reasonable thing to do but because psychologically those acts would feel too imposing, if science could not explain them at the time.