He drops his right elbow onto his hip early and leaves it there. An early return to the Elbow Plane maybe? You can really see how the Accumulator angles 4, 2 and 3 are the last things to go sequentially.
Could Hogan have studied this? It really reminds me of his Coleman Estate slo mo drill in terms of the downswing sequencing , ground up. 6-M-1.
Although here, in this drill anyways he gets his club off plane a tad in Startdown. Something Moe observed apparently.