I often found back when I was an airline Capitano that on the ground it was fairly easy to diffuse a situation by the Captain just being present.
Pax who had paid for emergency exit but had crutches, pax paid for xyz but some other issue, pax etc…..
I would never compromise the CSM’s position but merely assist. Often at times just standing in the galley when issues, amazing how quickly passengers would change their tune with CC when Captain came out.
Of course I have no idea what happened in this instance, however it is amazing that a situation can get to the taser point.
Not every pilot has the confidence to step out the flight deck (yes only on the ground), but as I said, personally I saw the change in pax behaviour several times by doing this.