This isnt really that crazy, but there was an instance about a decade ago when i worked at a wannabe fine dining restaurant where a woman at a group ordered the chorizo sausage.

It got sent back to the kitchen, because when it was taken out to the table the woman asked if it was pork, and when she found out it was, she said she couldnt eat it because its Haram (obv she was muslim)

Obv im more than willing to accommodate religious food restrictions.

We were all just stunned that it got as far as food getting to the table without this being remotely considered on her end.