The way he dealt with this is obviously not ok, but I think you really overstepped a line by trying to tell him what to do and clearly refusing to back down when he told you that wasnt what he was going to do. Obviously it's his responsibility to stop the conversation at that point without showing his anger which he clearly failed to do if this went on for the whole session, but I dont know why you thought this was an ok thing to insist on. It's one thing to explore your feelings about it, but another to try to tell him what to do, which it sounds like you did by asking him to keep an eye on the news. Personally I'd find that incredibly patronising.