This seems like a mistake to me. I don't see a way to win the race. I wonder if the point was that White now has a stable group, so this is a failure for black. White can hane underneath the stone on the right side, and should probably be happy with that - Black was stronger here to begin with.
You are right that the top right belongs to White with correct play, but according to the programme Sabaki White wins by one point (because they have a captive). It is conceivable, but somewhat unlikely, that White could make enough errors for Black to win.
Sabaki calculates the score like this for area scoring:
and like this with territory ...
I've read a couple of articles discussing the impact of AI on professional Go, the second one being a reply to the first one:
Impact of Go AI on the professional Go world
Impact of Go AI on the professional Go world, Response
Some quotes from the first article:
The second important change I see is the professional players’ race to
learn from AI. (...) it’...