The way I see this, even if you have a disability, its still wrong to complain as thats what the purpose of toilets are.
To me its just like someone who had a very bad accident and can no longer walk complaining that someone was using the stairs in front of them and saying this is insensitive because this inflames the trauma they suffered as a result of the accident.
This is a IABU, and the answer has been a quite responding yes, because the normal accepted purpose of a public toilet is to dispose of human waste products and although not typical, was a proper use of those facilities. The fact that you have issues with this, is not the fault of the woman using the facilities - anymore than it is your fault that you have issues, but you are being unreasonable in saying that she is being disgusting.
If you have aspergers, then part of dealing with it, is learning to understand when your reactions are abnormal to what others would do. You can not reasonably expect the rest of the world to understand everyone else's quirks of personality - whether they be a disability or just because someone has abnormal expectations of others - simply because society would grind to a halt trying to do so. You have to go according to what is generally judged as acceptable by the vast majority of society.
I get the feeling that you now see this as a personal slight, and are going overboard in defending what you believe. However tbh, its one of those that is indefensible regardless of your issues and one you have to bite the bullet on and accept that given the responses here, that your reaction is the thing that is wrong and not the woman in question.