Responses
I see what you mean and I couldn't agree more if it weren't for that one scene... The brother seems to be holding his pride above all else and it seems to be coming from his father as a sort of "making daddy proud that I am strong" personality. Therefore hearing his "stern strong prideful leader of a father" admit to being wrong, is high possibly mindblowing to the brother and could lead as a milestone in becoming a better heir to the throne.
Nah the brother still sucks, he's a horrible husband, father, son, brother and for such would be a terrible king. Already saw the kinda shit he would try to pull if he was king.