FFS they are diagnosed by professionals actually trained in this. It is ONE factor that is considered, but I’ll be sure to contact the two separate clinics, and the psychologists and psychiatrists to tell them you know better.
Per the NAS website: bold print is my emphasis.
Social communication’ and ‘social interaction’ are often used interchangeably. This includes the use and understanding of spoken (verbal) and non-spoken (non-verbal) communication, such as conversation and body language. It also includes social ‘exchanges’, such as sharing and taking turns.
Social communication and interaction skills are used to start, build and maintain friendships and relationships with other people, including in your personal life, in education and at work.
Social communication and interaction differences are part of the criteria for an autism diagnosis, but these differences can vary widely between autistic people.
Language
Language is a system of sounds and symbols used in communication.
Although language differences are not part of the criteria for an autism diagnosis, language is a significant part of social communication and interaction, and research suggests that some autistic people may have differences in how they understand and/or use language. This can vary a lot between autistic people.
As I stated their verbal communication is fine, but their lack of a fully developed theory of mind means they struggle to interpret motive, mood, facial expressions and some behaviours of those around them. This can lead to mis-communication. They are absolutely autistic.