There is a long interview of the pilot (J.P. Trimaille the FI ) of that flight in the March issue of INFO PILOTE ( French GA magazine ) he said there were on an IFR LPV approach for 25 in Toussus at 4000 ft descending for 3000 when the first engine stopped, the student ( already a CPL ) believed it was an exercise and followed the procedure but almost immediately after the second engine stopped, . He immediately took over from the Student and both tried to restart with fuel pump ,changed tanks etc, but losing alt fast .. It was almost night . a large avenue straight ahead , but full of cars , he chose a smaller space between 2 big buildings also almost straight ahead , he said he took arbitrarily 70 Kts as a compromise to stay above stall and minimize impact speed. he planned to hit the buildings with the end of wings ( the outer half wings ) to dissipate energy . All worked out almost as planed, the right wing hit the right building first which spinned the a/c which landed with little vertical energy. The door could be opened and they walked out. His lesson : keep speed to avoid stall, choose a place to put it down somewhere straight ahead. and fly the aircraft until the end
There was only 1 min 50 sec between the double failure and impact . So much for an 82 years old with 40.000 h . He is back flying again as an FI .I'll go with him any day.
He does not know (yet) what caused the double failure., the BEA is looking into it.