As an armchair quarterback, I'm gonna side with some statements I've heard from other airline staff; that the FA in question - be it drunk or otherwise impaired; it was caused by their own doing. S/he was either trashed out of their mind, didn't get much sleep (was out partying? with friends? with other crew members? - i mean there ARE 2 RON crews in Bos), didn't take their meds, etc etc.
What I do know is that flight attendants ARE required to be abled-bodied persons. While I am no AME (Aviation medical examiner), I don't believe that an FA is fit or proper for the CAREER should they have some physical ailment that requires constant medication or supervision. A friend I know was even released from work for being bipolar.
Whatever happened in Boston, under my own OPINION from statements from friends who work at BOS, was that this FA didn't just suddenly have this happen to them.
In the end, maybe we should close this thread. Not sure there's much to be gained from the repeated bickering, or the curiousness of those reading this as to what really happened... because if Alaska wanted the world to know what went down in Boston on the 13th of Feb, we'd know already.