If he was sitting near the door, he could go out easily,
and not be near the people sitting near him, but if he was
planning on going out, he’d have sat there himself.
(Rav Weiss did not address whether the actions of the
man with the possible medical condition were justified.)
While DaasYochid is correct in saying that “Sometimes we’re supposed to be nice to people even if they’re doing something wrong”, wouldn’t a Rav be a good person to ask if this is one of those times?
It would not embarrass anyone for the Rav to instruct
the gabbai on how to handle the situation, and that might
even prevent someone else from embarrassing the man.