Lots of problems with this painting, but two stand out almost immediately: Hickok resting the gun on his left arm, and the gun in the right holster, indicating (erroneously) that Hickok used a cross-draw; to be accurate, the right holster should be empty. Hickok was a master of the "reverse", or "twist" draw where the pistol is worn butt forward and the hands are turned under to grasp the butts with the thumb over the hammer spur. The gun is then pulled from the holster and is twisted around as it is brought to bear, the weight of the gun causing the hammer to cock. No cross draw involved, and very fast when used by an expert. Keith Carradine did an excellent job demonstrating this draw in the series "Deadwood". Old Fuff is right (as usual); the artist relied on legend and speculation when creating the painting.