My stepson with AS is nearly 12, and we have been discussing this issue for some time at our house. I am also a mandated reported so I know this issue from the other side too. Sadly, my step son has, at times, accused various people of "abusing him" when he gets overwhelmed or his sensory issues are really out of whack. Luckily, this is a documented pattern with his therapist, but more than once we have wondered. We have imagined how difficult it would be to explain this issue to a third party who doesn't know us or him.
We haven't done it yet, but our plan is to take him to the local police station and introduce him to the officers there. Then we will follow up that visit with a letter explaining his diagnoses and giving lots of information. He is really big for his age, and can be aggressive so we are trying to be proactive. We also have a family member who is a police officer in the city where is mom lives and he is the one would call on if something ever came up when he is there.
We also should probably know what legal counsel we would call right away if something did happen... but we haven't found the right fit for that yet.
I agree with other posters that the clothing issue is unlikely to be an issue, and even if reported, unlikely to be followed up on... but I would be ready and thinking ahead to when your child is older and out in the world without you. The AS parenting lists I'm on make me think that some sort of issue involving either CPS or the legal system is very likely in our future.