I suspect that the school event happened before the parents found out what was really going on, then the "you know what" hit the fan! No doubt intemperate language was used at home. You got a mere echo.
One of my sons had a bunch of Moslem kids in his gym class. Ordinarily his team (he was their leader) could beat any other team at any sort of team sport you can name EXCEPT when there was a girl on the other team.
When that happened my son lost most of his team mates because they refused to play in a contest against girls.
These guys are funny that way ~ more like your great grandparents than modern Americans for the most part.
Quite a long way from the grandparents of modern Americans, actually.
Yes, they are funny that way. In other countries they insist on using their own customs instead of that countries civil law. In others, they blow up something to get a governmental action or custom changed. In America they don't feel that strong.
Muslims don't assimilate. Closest they come is "go along to get along". That ain't sufficient when push comes to squeeze.