Responses
I don't think gjord knows exactly what happened aside from what ishimion saw when he infiltrated the castle. Yes, gjord is being a fucking asshole bitch but he wouldn't show him that, most likely is that the question triggered Sylhan's memory of the abuse causing to remember and "see it" reflected on the water

This is so fucking crazy let me tell you… i just reread this chapter and i realized i never commented on the biggest most disgusting part which also happened in the book. So Gjord knows that Sylhan couldn’t do anything about being assaulted but he still goes and calls what lister did to him “consummation” “sleeping together” “spreading your legs” “someone else crawling in between the heat” or whatever bullshit he was saying and then even SHOWS??? HIM THE TIME HE WAS BEING ASSAULTED??? Through the cup??? … like bro what the fuck is wrong with him? Mind you this means he knew abt this thing the whole time and didnt do anything about it..