I think he has shot himself in the foot rather by basically claiming to have no recollection of any of these encounters during police questioning - but now on the stand remembering a startling amount of the detail.
The prosecution will surely pull him up on this fact in cross. Of particular note is that he claimed not to remember the Apollo night / threesome - then suddenly say it was particularly memorable to be rimmed right at the start of an encounter ...
That seems a huge error and hopefully will lead the jury to find that his subsequent explanations are fabricated.
I would contrast this sudden remembering of details when it suits to the Apollo complainant who has so much contemporaneous third parties who relate what she said then - many many years prior to the Dispatches programme when Brand was viewed as a bit gross, but a "top shagger" and was immensely famous. She had nothing to gain back then from alleging anal rape in the context of consensual vaginal sex.
** edited to add - not that she has anything to gain now. Quite the opposite - a world of pain and some hugely private details subject to worldwide scrutiny