The earlier your selected Release Point, the sooner your Right Arm straightens. For example, with a Full Sweep Release, your Right Arm will straighten almost immediately at Start Down. With a Snap Release, your Right Arm bend may even increase slightly on Start Down, and it will not begin to straighten until your Hands are just behind the ball.
As your Right Elbow Cocks (or bends), your Left Wrist also Cocks.
As your Right Elbow Uncocks, your Left Wrist Uncocks too.
That's how you can have a perfectly Level Right Wrist whilst Cocking your Left Wrist. This maintains the integrity of the Flying Wedges.
For Hitters, it is the Right Triceps that Uncocks the Right Elbow and hence the Left Wrist.
For Swingers, Centrifugal Force executes both Uncocking motions.