These takes are just naive. You don't think people ever say retarded stuff at work or let their filter slip?
Heck one time my mom was out to eat, they brought her food ~10 minutes before everyone else's food for some reason, so she finished eating before everyone else and the waiter comes by and says something like, ""Wow, you really got through that quickly."
It's not as bad as the example, and my mom's not as fat as her, but it's not soooo unbelievable that a waiter would ever say anything that can be perceived as rude.
Especially if it was a french restaurant, then it's just part of the experience.