Could the poles have been moved to a position clear of the wires?
I suspect that what we are watching is the removal of old poles from the right of way. The terrain is steep, the cleared right of way narrow and any moving of poles on the ground would have to be done by hand. If they could have gotten a tractor in to clear more land and move poles, they could have used it to drag them to the nearest road. Far cheaper than using a chopper.