You're honestly telling me that you don't see the arm slowing down as the club passes it around impact during the swing shown at the 41 second mark of the video (it does during all of the swings, but this one is at full speed, so no one can claim that the film was slowed around impact)? Sure it's accelerating from the top. No one is discounting that, so I hope that isn't your argument. But it isn't accelerating through the entire swing. That arm slows as it gets perpendicular to the ground.
Bigwill - I viewed the video several times frame by frame during the slow motion capture of the robot overlaying the human golfer. I agree, at near impact position the robot arm clearly appears to have a slower angular velocity than during the downswing. Could be the oblique camera angle but I doubt it.
Even if it didn't, I'm not sure what it proves as I would think the robot could provide much more torque than a human golfer - maybe it would be the goal to shoot for but rarely (if ever) attained by real golfers.