From his description of his descent (sliding ON HIS FEET, grabbing for a cable handhold, eventually scooting down on his butt), I'd say the salsa dancer's "skill" didn't help him much.
It's a 40% grade, steep as any ladder. You ascend a ladder by facing the rungs and holding the sides. You descend a ladder by (again) facing the RUNGS and holding the sides -- NOT by facing outwards and standing erect.
Someone with a decent amount of physical education should know something about his body's center of gravity and the advantages of keeping it low.
I had to jump off a ladder yesterday because I decided to descend facing out and got overbalanced.