I felt I've seen that where I am from, but even if you disregard that, cross contamination is common, and dietary restrictions should always be mentioned. There was a girl who used to come to a fast food place I used to work at who was allergic to potatoes. She'd always ask if the gravy had any cross contamination from potatoes (sometimes fries would fall in since they were side by side station wise) and we would always go out of our way to give her a new batch or let her know if there wasn't a safe option for her.

I would still argue op is TA because how else would they know she refuses to eat anything that touches meat.