I have to say that I would go along with the overstress theory. If they did suffer a failure and subsequent separation of number one engine, that close to the ground, and an encounter with wake, the temptation not to slam on as much rudder as possible must have been insuperable. The left engine is on the inside of the turn for a Breezy Point or Carnarsie climb, and the sudden loss of power and significant disturbance in roll ensuing a separation would have left controlability marginal to say the least.
I suspect that the sudden application of full rudder coupled with the lateral load due to the thrust assymetry was simply too much for the vertical stabiliser. A truly tragic accident, and one that all of us would have found virtually impossible to counter.
I was crossing the pond at the time, and it sent shivers down my spine as the incident was reported piecemeal over the radio. I feel deeply for the colleagues of the AA flight crew as they heard bit by bit of the demise of their colleagues. The tremble in the voice of the New York controller was palpable as she broadcast 'suggest you utilise all prudent security measures'. You could hear the 'Here we go again' being pondered by everyone involved.
I feel ashamed to say that thank God it seems it was only an accident. For those who have lost loved ones, it is disaster just the same. Deepest sympathy.