Ignoring the political things, Mueller is providing damning confirmation which adds weight and context to the report in a substantial way. That he isn't banging the table is irrelevant as well as fantasies of angsty revenge. He isn't weak as demonstrated by his seeming amusement at people yelling at him. It has taken a bit of time to get the feel of the room, but he's not falling apart. I suspect his hearing troubles make him appear confused because he has trouble locating speakers, and his health appears to have suffered. But where it matters he has delivered, providing ample cause and opportunity for impeachment. Now the ball is squarely on the shoulders of Pelosi and apologists cannot free her from her responsibility, actions or lack thereof.