How frustrating!
I have a child who is dairy, gluten, red dye free so I provide substitutions. BUt then one day dcd tells me that dcb is a string cheese monster!
That they have been trying cheese with him and he's been eating the crap out of it, but they never told me! I have a feeling that they are just saying he's intolerant of these things (they do have a note, but it's not hard to get). I take my time and extra money to buy his food free of these things and then find out about the cheese.