With the current focus on the flap configuration, some consideration might be given to problems associated with an abnormal flap approach and landing scenairio. These are general comments, not necessarily about the subject accident, and should be taken with a pinch of salt.
In a swept-wing jet, it is difficult to control speed on a 3 degree approach accurately at VRef with flaps at reduced angle and especially with flaps retracted. This is due to the low drag configuration and unexpectedly and low engine RPM required.
The common error seen in training is for the pilot to stabilize the speed at 15-20 knots above Vref and then for the pilot to experience some difficulty in reducing the speed in a timely manner to Vref. The higher approach speeds associated with reduced or zero flap angles further reduces the time available to accomplish the tasks necessary to line the aircraft up for landing and carry out the standard and abnormal checklists.
If the approach speed error is significantly above Vref, idle thrust must be selected to allow the speed to creep back to the correct speed. If the pilot's attention is diverted and the speed is allowed to go more than about 10 knots below Vref, the inherent low response for jet engines to spool up from idle and the very high induced drag (on the backside of the drag curve) can very quickly result in even further speed reduction with a very high vertical sink rate situation.
At the best of times, landing distance required is very limiting with reduced or with zero flap angles and therefore it is critical to achieve the correct touchdown point on the runway at the correct Vref speed for the configuration, so that the aircraft may be stopped in the remaining runway length.