AFAIK, CP is self-diagnosed.
Mike the programme publicity stated Chris Packham was diagnosed as having Asperger's in 2005, and has spent the time since then coming to terms with that diagnosis.
I found the programme very illuminating and came away with respect and admiration for CP. I understand now that autism is part of who he is and he feels it to be a gift which has enabled him to succeed in his field. He seemed, on the face of it, to have found a balance in his relationships.
I have worked with people affected by autism in varying degrees, and I can relate to the concept that no cure is required but rather understanding and nurturing. In mental health this is probably not the cheaper option which is why people are finding themselves being forced into mainstream society. The US section with regard to Silicon Valley tech companies employing and mentoring people with autism was good to see.
ABA may be society's answer to autism but it may not be autism's answer, is what I took away from the programme.
I hope CP continues to present his fascinating programmes, his enthusiasm and intelligence are missing in so many presenters on scientific subjects. I won't name them...