Jean Whitmore - Video Analysis
Stance looks good but no back lift. His hands are pretty much stationary as he lunges towards the ball. One of the tell tale signs is that the leading front shoulder is not dipping towards the ball forcing the hands back past the back pocket. More of a lunge rather than a strike. He is also playing the ball way out in front due to the extension of the back arm, if he keeps the back arm bent he will end up playing the ball later.
Much better here, slight dip of the shoulder to the line of the ball, hands go back a little and right arm is bent therefore playing the ball late.
In this video, there is no commitment to a full ball. Front foot movement is poor and because of it he ends up hitting his back pad before hitting the ball
The front arm is coming across the body. I would like to see this arm a bit taller and straighter.

Collapse of the front leg is something that we need to work on.

Simply work on the lateral flexion
Although his running action has improved he is still replacing his feet / cross over gait. Everything moving in parallel lines and towards target leads to a better alignment and balance
Just a different view.

The leap I think is rather large which might be contributing to the inability of locking the front leg

Lateral Flexion need to get you bowling more upright