I only noticed his right hand grip coming loose in the backswing (in the 1st video) and maybe his ball position a bit too far back in the stance with the driver.
But how would one define an 'early extension'? Is it when the golfer thrusts his hips towards target line immediately during the start of the downswing or just before reaching P4?
Early extension is i) when the right buttocks prematurely leaves the tush line and ii) the golfer simultaneously loses his anterior pelvic tilt thereby decreasing the spinal bend inclination angle (as seen from a DTL view) during the early downswing.
I would look at how he hinges and rotates the club going back. The way he sets the club at the top of the swing causes him to cast. You can see how his angle of attack is steep and the clubface open. That caused the toe hit on this particular swing.