Release with lead-wrist extension, trail-wrist flexion
Through impact the lead wrist moves into extension while the trail (right) wrist moves into a flex position. According to the speaker this is not the hands rolling over, even though it can look that way; you can still see a lot of the lead forearm.
Channel: CraigHansonGolf
Watch official source at 3:02Why this context matters
Craig contrasts this against the common belief that the release is a hand roll-over.