That's exactly what happened. Joe is well-known for having a nasty temper, but he knew he couldn't give in to it at that time. So he sank into himself to contain his anger.
Also, while there is no question he is not as vigorous as he was even a few years ago, I also don't believe he is as far gone mentally as some assume. He is just what he has always been...a man of mediocre intellect and abilities, zero leadership qualities, and the sense of privilege that came from his decades in our equivalent of the House of Lords, the U.S. Senate.
Biden is a fine example of why the 17th Amendment should be repealed !
The Delaware State legislature couldn’t do worse and even if they did not for 36+ years !