this is one of my top picks in the challenge. incredible shot--great dob, focus, composition, colors, and definitely meets the challenge. the only thing i could offer for improvement would have been to have backed off a step and pulled around slightly to your righ so that you wouldn't have cropped off any of the cowboy (then, again, with a moment like this, you might not always have the opportunity). way to be there! hope this does well.
IMO - you nailed the challenge. The smoke adds such a necessary dimension to the photo. My suggestion - maybe softer shadows or some detail in the cowboy's face.