Gedney - I would expect that he only has a very light contact with the ground such that he is essentially in the hover rather than having landed - this would allow lateral cyclic and the most minimal addition of collective to effect a flyaway, even if he dragged the skid a bit towards the cliff edge.
Try doing the same thing with both skids in contact when the only option is a rearward movement - not impossible but much more difficult.
I agree a winch-equipped aircraft would be better but many countries don't have that facility either by choice or necessity.