something I would do

Well, that sucks. It's okay, everyone makes mistakes. At least you tried to make his day better

I'm sure he knows you didn't intend to be rude or anything, we all fuck up like that sometimes :)

That sucks for him. I don't think he will care that much though, you were trying to be nice. Good on you.

nice customer service

It could be worse, you could have just switched over from a fast food place and asked him "do you want fries with that?"

You'll be a good staff in a Pokemon Center. The nurses there says "hope to see you again" after you just brought your dying pet.

Imagine if you said good luck

He probably didn't care...

Well to be fair, what you said was better than telling him to have a bad day.