The topic was this case - not the coffee one - and in the first post about this case it was written that the children had
celiac disease. Even if there is no link between gluten and autism, there is one with celiac disease.
French fries are supposed to be made of
potatoes, fried in oil or fat. Their foot info says it's free of gluten. If you take your kid to McDonalds - as it no doubt wants that so badly - and their information says their fries are glutenfree, it would be perfectly reasonable to expect their French fries to be glutenfree.
Edit: A final note, the article said that the law suit claims their autism
symptoms aggravated. I imagine that the bowel inflammation - and it's possibly discomforting symptoms or it's effect on digestion - might indeed aggravate some of their 'autistic symptoms'.