I think it's fairly common to recognize someone, but if it's in a different context not know who it is they actually are. For instance, if you see your dentist in the grocery store one day, you may recognize him as someone you know but it doesn't occur to you that he's your dentist because he's not wearing his dentist outfit and he's not in the dentist's office.
I don't think this is an AS trait.
I sometimes have the opposite problem, where I'm convinced I recognize someone as person X, but in reality they are someone else I've never met. I will point out the similarity of this person to another person, but she will say, "No, they don't look at all alike." I think it's because I zero in on particular details of a person's look, and if most or all of those details add up, it really looks like the same person. I guess my wife either sees different details or she sees more of them.
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"That leap of logic should have broken his legs." - Janissy