Basically, the stall warning horn coming on only just before shows the pilot to have reserved the final amount of lift available as kinetic energy for the area of “ground effect” (similarly for water). It means he pulled back on the yoke just before touching down, which is a good piloting technique for hitting the surface at the lowest possible speed.
HF
IIRC, he is a retired commercial airline pilot and a license glider pilot.
So for the first ten seconds of the video there are no warning alarms sounding (cabin and cockpit are silent), then ten seconds of stall warning until impact is not unusual?