Interactions with people are a difficult, complex thing. However, we do it pretty well. Before we say something, we consider how we would take that comment. Cause and effect teaches us that this comment will make someone feel good and this comment will make someone mad.
A person with autism has trouble with this. They say what is one their mind because they cannot predict how someone else thinks (to generalize). They do not see social constructs.
. Otherwise you leave them in the dark of what is wrong. Focus on helping them not make the mistake with someone else.