I didn't see anything to that effect. I suspect that, if it goes that far*, he'll maintain the line that he had no recollection of meeting her (to avoid giving a hostage to fortune), and not admit the authenticity of the photos. I guess he could probably find an expert witness who'd say they could be a fake, but not sure he'd bother, given they don't prove anything anyway.
*I doubt it'll get as far as being disputed on the substantive evidence - the claim will be barred as a result of the previous agreement, or there'll be a jurisdictional challenge, or he'll settle, or allow judgement in default on the basis it can't be enforced agadir him in the UK.