Consider the first diagram in the linked paper (a, pg 2). It is pretty obvious that black could have killed the internal group in the top-right corner at any time for ~26 points. That'd be about enough to tip the game. Instead somehow black's group died giving white ~100 points and white wins easily. Black would have had ~50 moves to kill the internal group.
Or if you want a replay, try https://goattack.far.ai/adversarial-policy-katago#contents - the last game (KataGo with 10,000,000 visits
- https://goattack.far.ai/adversarial-policy-katago#10mil_visi...} - game 1 in the table) shows KataGo with a trivially winning position around move 200 that it then throws away with a baffling sequence of about 20 moves. I'm pretty sure even as late as move 223 KataGo has an easily winning position, looks like it wins the capture race in the extreme lower left. It would have figured out the game was over by the capture 8 moves later.
So dead man walking is a bad description. From your perspective it's still KataGo winning but a series of serious blunders that occurs in these attacks positions.
Or if you want a replay, try https://goattack.far.ai/adversarial-policy-katago#contents - the last game (KataGo with 10,000,000 visits - https://goattack.far.ai/adversarial-policy-katago#10mil_visi...} - game 1 in the table) shows KataGo with a trivially winning position around move 200 that it then throws away with a baffling sequence of about 20 moves. I'm pretty sure even as late as move 223 KataGo has an easily winning position, looks like it wins the capture race in the extreme lower left. It would have figured out the game was over by the capture 8 moves later.