[He could say 'you could have believed us' but it's too late at this point. But, even so...]

There was always something else you could do.

No one made you make this choice. It's not like the Kingmaker's trials where you're guaranteed to die if you don't condemn someone to death. You could have tried to escape with the rest of us, found out if there was a way from any of our worlds to find a missing person. You had a decision, and this is what you settled on.

It's not one I don't sympathize with. Far from it. But you did have the choice.