Outrageous slander.
Ben & Jerry had been trying it via a completely bizarre sequence going initially with the right hand. They couldn't do the first move. I'd been trying it without success using the now accepted beta, I couldn't do the last move.
One day, Jerry was there the same day I was trying it... Not sure where the idea that Ben had new beta came from - that's not how I remember it.
20-odd years later I've still not done it.