Putting aside the fact that the figure is in shadow there is much to like about this image. However, as it is submitted for critique I will pick up on a few areas where there may have been room for improvement.
The placement of the head is uncomfortable in so much as it just brushes the sky. Ideally I would have like the head to be comfortably below the skyline, which would have required you to shoot from a slightly higher position. This may or may not have been possible, but I feel it would have strengthened the image.
I think I would also have liked to see the anchor point on the right, although this may have unbalanced the shot a bit pushing the figure a bit too central. Perhaps that could have also been counteracted by going a little wider on the left. You were operating at full zoom so I feel you could have backed off slightly to get the wider shot.
Using flash may have helped overcome the shadow situation, and would also have helped you control the background exposure a bit better as the far hills and sky are a little more washed out than I would like. Of course I think it would be prudent to ask your subject if you could use flash as he looks to be in a precarious position and I wouldn't want him startled by an unexpected bright light
However, despite the above points, I like this shot a lot and feel you have done a commendable job.