"Even if you have eyewitnesses”. Suppose from the 1850s, we have an account of a pastor of a church in Kansas who walked across this pond during the fourth of July on a celebration, and there were twelve people who saw him do it. The historian will have to evaluate this testimony and have to ask, did he probably do it or not? Now these eyewitnesses might have said that he did it. But there are other possibilities that one could imagine. There might be stones in the pond, for example. He might have been at a distance, and they didn’t see him. There were other things that you could think of. If you were trying to ask for probabilities, what is the probability that a human being can walk on a pond of water unless it’s frozen? The probability is virtually zero because in fact humans can’t do that.
I might have more to say on this later, after a more thorough reading and an opportunity to digest the contents.