At 3:20 in the video the limpwristing is pretty evident. There's one good shot, then a bad shot.
Your hand appears to be over-rotated towards the trigger and your thumb is not securely wrapped around the opposite side of the pistol.
You're also shooting with a 1 handed grip. Looks almost like your off hand is gripping the fore-arm of your shooting hand? Use a two handed grip. Both thumbs line up next to each other and keep counter pressure on the rotation you otherwise would experience when shooting one handed.