1. Lifting the gear may produce a longer glide angle, but drag will increase to start with, gear is powered by centre hyds, two big air driven pumps and two little elec ones I think, who knows how these systems were going to be working at that time, result could have been just more drag and some of the gear not locked down or half way up and pitch changes going on and poss slow operation of flt controls due big hyd use on gear.
2. Changing flap setting may produce a longer glide angle, but due hyd issues and the need to change pitch and so close to the ground appears a close call either way.
With both of the above and headwind/tailwind to take into account, the Aircraft would of had a best/max glide angle config, appears the crew got it right, any shorter did'nt look nice and much further could of been a big problem going on the paved surface at hi speed, I guess there is a perfect point, config, speed, pitch and roll for an undershoot, looks like they were very close on all counts, well done !!!