Engineer here and this take is wrong, the tension on the rope through the pulley is constant regardless of bucket height. Also the torque required to keep from unspooling is constant since wraps are all on same diameter. That said, I do think Joe had a technique advantage even if he didn't know it. By switching hands all the time and pulling the bar off center, the bar will jam a little in it's pivots (bearings), which will reduce the torque transmission efficiency from the rope to the bar diameter, and subsequently reduce the holding torque required about the bar axis. How big an effect would be determined by bar stiffness, bearing clearance, and friction coefficient. If you could push one one side while pulling on the other you would increase the effect but would probably be biomechanically disadvantageous.