I believe the negative beta force is what causes the lead wrist (left wrist in a righty golfer) to bend back on itself to and through impact.
Ya, past the ball into the follow through as the club head gets behind the body and away from the ball would be a negative beta, huh. Didn't really think of it that way. But, I don't think it's an active torque from the golfer. Sometime after impact is a coast to the finish.