Too much speculation without all the facts... especially from the DCVR. That would probably shed a great deal of light on what the situation was. Perhaps the transcripts from the recorder will be made available if the NTSB holds hearings on this incident.

Proabably the most important thing to bear in mind that no fatalities occured.

After how many have puckered up at the approached TOD after a long journey with unexpected ground delays at the departure airport, stronger than forecast head winds, longer than usual sequence vectoring?