When I was a teenager, a little girl I babysat had a milk allergy, and died after two bites of restaurant oatmeal which her mother had been assured had been made without milk.
Specifically, she died of anaphylactic shock in the car where her parents were racing to a hospital. I found out the very next day, when the mom came into the bank where I worked (back then, teenagers had jobs, including jobs in places like the small neighborhood bank).
I had enough home-training not to say anything abusive like, what the hell were you doing in a restaurant with such a severe food allergy???
But ever since then, I've always thought that a known lethal allergy is just not something you can safely bring into a restaurant (especially if you'd like to eat something that is typically made with the forbidden ingredient). Call it trauma. I never got over the image in my mind of that mom in that car.
I appreciate where Achatz is coming from. That was the most distressing shiva call I have ever paid, and it was a good 33 years ago.