Why would a pilot use ailerons for countering asymmetric thrust in mid-flight?
This AOPA article "PROFICIENT PILOT LAZY-RUDDER SYNDROME" written about this incident, presents an interesting point of view on the matter, that basically good design and complacency leads to little regular rudder use so in emergencies its initially over looked. 


  This pilot might have been affected by "lazy-rudder syndrome," the
  reluctance to use a rudder to the extent dictated by given
  circumstances. Some believe that this reflects a general decline in
  basic stick-and-rudder skills. A commonly observed symptom of this is
  lowering the right wing during initial climb after takeoff to
  incorrectly compensate for a single-engine airplane's left-turning
  tendency.