Flaps & SG,
I'd resist any move to circumscribe the aircraft commander's action in any given situation.
Whether, with hindsight, the captain was unwise to speak to these people, I'd throw the book at anyone who assaults any crewmember, but especially the captain. (and I do say 'especially the captain' advisedly)
(not if the captain assaults a crewmember but you know what I mean
)
p.s. Noted not travellers - I guess that's why my previous posting was removed