Well, -I- didn't bring it up. Why did the article go to the trouble of stating the Mexican flag bit, without telling why?
Any question of illegality of the kid are out of bounds. Having said that, those comments were probably made by people PO'ed about the bit about the Mexican flag. As an immigrant myself, I now live in the United States and do not expect the flag of my home country to be flying at my high school even if I die there. Even when foreign heads of state die we lower the American flag at half mast. This multicultural crap is only dividing us.
I would be honored to have the AMERICAN flat flown at half mast when I die. There is nothing more symbolic in my acceptance in this new country as having that happen.