Saying a child is unable to tie his shoes because he has ASD is the equivalent of saying someone is fat because he is Canadian. He's fat because he eats Tim Horton donuts all day. Canadians, it seems, are statistically highly likely to visit Timmy's on a daily basis. If you teach the Canadian to shy away from fast food, he stops being fat. But he's still Canadian.
Teach your child to tie his shoes, and he's still autistic. So it wasn't the autism.
Break the behavior and you break the problem.