I haven't been able to get through that part in a satisfying way either. I've tried the knock out option but I think that mechanic is currently broken. After a couple of rounds of a character being "knocked out" they bleed out on the floor and die.
What breaks my heart is they tell you to save yourself or that they don't want to hurt you if they pass their wisdom checks.
I feel like there should be a mid-battle way to incapacitate them or save them. It's really upsetting.