What is that a response to? my claim that Poincaré beat Einstein?

Yes

That's not a relevant credential,

Not only does he have very deep subject matter knowledge, he's also studied the history in detail (as comes across to some degree in his Amazon review).

He might simply mean that Poincare took several papers over several years, while Einstein got it right in one try.

I don't know what he had in mind, it's possible that you and he are on the same page, I just thought I'd point you to the review because it seemed to be in some tension with your claim.

As for the rest of it, I don't have comments right now  –I was responding specifically to the Einstein / Poincare thing.