This feels like anxiety more so than anything. I literally walk around everywhere with sunglasses and headphones. I'm not ASD just sound and light sensitive do to physical damage. Not a single person has bothered me about this even during conversation. I chat with big ass cans on my ears. I go to stores at times where people aren't there and favor pick up if I can't do that. It's not that I can't interact. I just get really irritated by crowds and why do that to myself if I don't have to? I do self check out when possible because it is just faster and I always get irritated by how they pack things.

Stumbling over your words? Oh well. Who cares. It's a cashier. I did this all summer in a foreign country. Toddler talked my way through it and honestly with everyone. It's not exactly the same, but the pressure is. It's incorrect speech with a person you'll never see again or who won't remember you. Who cares?

Like this all feels like anxiety and lack of problem solving. And I'm not sure I even forgive it because my kid has autism and anxiety and she has solutions for these problems. She's not perfect, but she seems to be carrying on better than what you're portraying here. I also know several autistic people where what you're talking about is just not a thing. I get if you know an autistic person yoy know that autistic person, but they are coming up with solutions that allow them to be without a higher level of stress than anyone else.