From my experience working around many teacher and parent volunteers I noticed the difference between a good parent of autistic child and a bad one.
Good parents are easy going, they don't anger easily and are pretty forgiving. They seem to have this patient air about them. Aliens invaded Columbus? Great lets invite them over, Godzilla attacking? Oh neat! Lets all get pictures! Hell froze over? Lets go skiing!
If a kid has meltdown in front of people. They ignore it and let the kid work it out himself unless it's a self-injurious one. They are willing to listen to all kinds of information and are eager to learn. They don't worry if the kid ruins a shirt, breaks a glass or losses a hat. They care of their children of course, but the don't sweat the small stuff. Each step towards independence is to be celebrated. Most of all, they work to help make his life easier. The bad ones of course. Are the opposite, they stress out too easily get embarrassed too fast and seem not to have that flexibility the good parents have.
Also when I have a question, I tend to ask the good parents, because the bad ones never seem to have the right answers.