Iy would be ridiculous for the whole crew of a deep-pockets company like American Airlines, risking their jobs, to deboard a family based on their religion, if it was proveable.
The family was given an overnight stay in a good hotel, with meals paid for, and flown home the next morning. Perhaps AA had a morning flight that had enough empty seats to sequester the family a few seats away from the rest, if necessary.
Think it through. Im the little country towns I lived, there comes a season comes when wild leeks (Southerners call them "ramps") find their way to the table. The odor they impart to the eater is so bad that a child whose family had them was barred from school the next day, and maybe more than one. The problem is that when you do eat them, you are not offensive to yourself.
How this was dealt with in these little towns was to have a ham-and-leeks communal banquet every year. thus allowing ebery one to enjoy them in season, with no one being put off. I actually have a trophy ball cap given out by a northern Pennsylvania hill town memorializing theirs.
But if one of them tried to board a flight from the county airport the next day, I'm sure that person would be told "No."
This little family might have gotten into something like that--a meal with garlic-laden gefilte fish or borscht or something like that, not realizing the scent they bore from it.