At time interval 19:22 to 19:34 he got the direction of the deflection of the aileron bassakwards. For the right wing to go down the right aileron must go up (unless you are experiencing very rare and unusual flight control reversal due to things like a stall or spin).
I believe Jacques Cousteau had a son who was killed when the aileron controls for his seaplane were mistakenly improperly reworked during some maintenance and he tried to fly it with the connections to the ailerons causing the ailerons to move in the wrong directions with input from the flight controls. It is a very easy mistake to make.
Over the years I have seen several RC aircraft brought out to the field with the ailerons set up to move in the wrong direction. I have even seen an other instructor take off and crash a beginners RC airplane because the ailerons were set up to move in the wrong direction and that instructor did not properly inspect the beginners aircraft before the first flight.
I have caught a couple of beginners RC aircraft that had the ailerons set up wrong before the first flight.
I thought the same thing, but I believe he was trying to keep it very simple, and describe the force the aileron was imposing on the wing, and the motion that wing would impose on the aircraft. Otherwise, I agree...I've never flown, but I fly R/C and that is always something I check before takeoff!!!