Unfortunately, no. You must actually board the plane and have your boarding pass scanned (or the agent must otherwise input it into the computer) in order to receive flight credit.

Unlike some other airlines (e.g. UA and their EQM bonuses for using the Platinum Class Visa Signature), AS also does not offer any other way (AFAIK) to receive elite qualifying miles. You must sit your butt in the seat to earn status. (Many around here would say that's how it should be!)

However, an extension of this question: what if you started to walk down the jetway and then turned around and walked back out--and no one noticed? As far as their system would know, you had boarded the aircraft.

I'm sure there are security protocols to prevent this from happening, since this could possibly be a terrorism risk (although we've all seen that terrorists are not stopped by the mere threat of death...), but I'm sure it could be done...