S.D.
it sounds like he did hit her though, as you stated this is what he does. so he did hit the lady, and it doesn't sound like she was being cold, but was drawing attention to what he did to her. She may not understand autism at all, so you have to cut her the same slack you give your son. As with autism he can't always explain his actions, and you can't expect everyone to understand him, and his actions.