I really hated the delivery of the line "I thought you said he betrayed and murdered my father?" Luke shows very little emotion here. It would make sense for him to be mad at Obi-wan or startled or something. Obi just comes over and is like "Hey Luke, I know I told you a terrible lie but lets have a long talk and tie up all the loose ends huh?" I think ending the scene with Yoda works well. not everything needs to be answered. I think Return of the Jedi was too light in mood for the trilogy's finale and needs some much needed tension and suprise moments.