Couple of things I heard/read that do not change the main point of the event:
There are two children. The boy is a little older; he is the 'special needs' child, and was not wearing a mask.
The two year old girl, also maskless, was EATING yogurt, when Miss Karen Thing of the Airline demanded the family deplane, resulting in all the passengers deplaning.
Upon being allowed to again board the plane, Miss Karen Thing of the Airline was absent.
Several of the other passengers did defend the family, which is probably why the whole of the passengers was temporarily removed.
I haven't flown in years, was validated in my decision to boycott after the post-9/11 TSA Kabuki was enacted, and absolutely further validated now that the Faucian Bargain via the mask-Nazis is in force.