It would've been lovely if someone had directly interrupted this "John" anytime he attempted to expound extensively after being asked a minor clarifying question. This sort of person shouldn't be tolerated, not even by employees.
Trouble is has that he seems to be in charge of their bi-annual reviews, which is actually rather solid leverage.
Every dev team I've been on has always had one person that readily answers any minor or rhetorical question without missing a beat. I thought they were universal but maybe I have just been lucky.