First of all, does your friend have AS or is on the autism spectrum?
I have noticed this personally with certain friendships or attempted friendships. I am not sure whether there is something there or, it is just an aspect of an obsession with a person.
I first picked up on this a couple of years ago. I had somewhat of a reunion with a casual friend/acquaintance from my childhood. Sadly, we reconnected under conditions in where he needed some help (his home and community were devistated by a flood). I never picked up on this growing up, but I noticed that he had some AS type symptoms, and in theory we had some common interests. I felt kind of a bond with him, but again, I am not sure if there was something there, or it was the fact that I was a little obsessed with him. He did take somewhat of an interest in me for awhile, but after about 6-8 months, things broke off and we have only spoken briefly since. Ever since this episode, I have noticed a little bit of a bond with others from my past and present as well.