I'd think that when shooting at sunset, you'd get that glow, which I really like. However, there is not enough separation of the subject from the background, and the tones are such that he blends in with it. So Tony's suggestion makes a lot of sense to me. It also would have put more emphasis on the spray of water in the first. I think your images are really good, but could be even better if you can reduce the background intrusion.
Edit: looking at it some more, maybe the next time you do this, you could also put a flash on (at maximum long-range setting) and arrange to have the backlight (as in the first image) really light up the water spray, then fill in the shadows (ie, your friend) with the flash. Chances are that your flash exposure won't be visible in anything except the darker areas, which is what you want.