Autism diagnosis does not really focus on social interactions. Difficulties in social interaction are a side effect but it is not how they diagnose the condition.
https://www.autismspeaks.org/autism-diagnosis-criteria-dsm-5
"""Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history...
Deficits in social-emotional reciprocity...
Deficits in nonverbal communicative behaviors used for social interaction...
Deficits in developing, maintaining, and understanding relationships... """