Because the imprisonment is all the Regent's fault?

I didn't get the impression that Zhu Jiu was particularly rational in assigning blame, but anyway, I just rewatched that scene and Zhu Jiu goes back to the pillar with his face wound streaming blood to swear loyalty to Ye Zun, which must be right after and implies that a) he didn't go to prison and b) Shen Wei just... let him go after that one swipe? Thought he was dead (don't see why he would think that given the comparatively tiny facial wound)? Idk, it honestly makes even less sense on rewatch.