As much as a horses behind Biden is, this seems like friendly locker room type banter and not anything really malicious.
You'd think an experienced politician and so-called "man of the people" like Biden would answer “we're working on it, buddy!” instead of standing speechless, getting pissed, and then turning back around to call the poor guy a “smart ass”.
Things must be really tense behind closed doors in the White House. That seems basically a scripted line by the manager, and Biden whiffed the softball lobbed at him.