Bad Boy
Aren't you glad you asked?
It's hard to answer a query about a hearsay statement, because we can't ask the Jesuit priest what he meant by "physical evidence" or how he might distinguish a "historical Jesus" from what might well be his belief in a supernatural Jesus. We here can only guess. Here's mine.
If he isn't distinguishing historicity at all, then his statement is almost tautological. The question of a supernatural Jesus isn't a physical one, and so it is unclear how any physical object or situation could bear on it. So, let's assume he meant some historical Jesus.
If he was a lawyer, or chose his words like one, then he would be talking about the kind of things mentioned in jest by
Craig B in his post on the first page,
But we have alleged evidence in the form of his foreskin, umbilical cord, tears, phials of his mother's milk, bits of the manger in which he was born, samples of his blood; as well as the nails and bits of the cross used to crucify him, the notice pinned to his cross, samples of his swaddling clothes, and innumerable other things. Crowns of thorns. There's no end to them! What more could we need? His shroud? Well, we've got that too!
In other words, something other than verbal testimony, business records, and what we actually have, redacted reports of traditions about the man. The problem with all the things on Craig's list is that we cannot exclude for any of them that they were manufactured or procured much more recently than Jesus is supposed to have lived. In many cases, it is breathtakingly obvious that they were just that, relatively recent fakes.
So, if that's what the Jesuit meant, then his position is respectable. There might be some cavils about the shroud and the titulus, since some people remain unconvinced of their fakeness or misattribution, with apparent sincerity. In that case, where some actual analysis is called for, many modern theories of evidentiary reasoning (for example, the sort of thinking ably represented here by
Cavemonster, and a category which includes Bayesianism, which has also been mentioned in the thread) urge evaluation of evidence by a comparison of:
the plausibility that the object would be present, assuming that Jesus lived
versus
the plausibility that the object would be present, assuming that Jesus did not live
As with all evidentiary evaluations, people will differ in their assessments. Many people would say, however, that if they found the two plausibilities of nearly equal conviction, then the object is "not evidence," because its existence could not possibly change anybody's mind (or very many people's minds) about the uncertain question, at least not those who agreed with the equipoise evaluation (or near-equipoise).
So, it is likely that your Jesuit informants' statement is a truthful account of his beliefs on the narrow question of the physical evidence for some historical Jesus. It would be easier, though, and we could be more definite, if we had the opportunity to speak with him directly. It would also be interesting to hear the rest of his argument, of which this statement was a part.
Hope that helps.