Cooking for other people can be stressful. When I’m cooking for myself, I don’t have a care in the world. If it’s gross, who cares? I’m the one who has to eat it, so I’m only disappointing myself. Plus, if I’m the tiniest bit lax with food safety (aka using yogurt that’s a couple of days past its expiration), I’m the only one taking the risk. This all changes when you cook for someone else. You literally have their life in your hands, especially if they have an allergy. Even if you take all the precautions you can, they’re still putting a ton of trust in you. 

This is why some folks with allergies don’t love to eat meals made by people they don’t know that well. It’s understandable. The risk/reward ratio is way favored in the risk category. This is especially true if the person cooking for you is like the guy in this story.