"He's a good man, but this has been very hard for him." Not meaning Jacob's return specifically, but having all his friends and contract partners end up in the Pit, having to go search for them. It had clearly hurt him, and Jacob does feel partly responsible for Vrenille's pain, because he didn't walk out of there. He shouldn't have been kidnapped in the first place. But even Vrenille and his magic powers can't change the past.

Rosita's confession earns a small tug at his lips, a little smile that withers quickly.

"No one can be right all the time. But in that time and place, you were right. You had experience and logic behind you. I was young and stupid." And he hadn't done any good. He hadn't stopped people dying nor had he made this better for those that didn't die. But her saying that... he knows what she's getting at. He knows it's coming from a kind place.

"I'm afraid I can't tell you a moment of sudden realisation, I simply... knew it. I think having the time I've had, the things I have seen and experienced? They have made me more inclined to watch and consider before I make a move."

In short: he grew up.