Nice looking chap. You should either blackmail or bribe him more in the future.
As far as the photo goes,...
Good camera position but bordering on the high side. Nice vertical position of the eyes in the frame. However, I think you should've taken a half step to your left so that there is a bit more negative space (direction of gaze) in the left edge of the frame. This would also have closed the gap under his right armpit.
The forward roll of both shoulders gives a diminutive essence to his character. Next time (in similar camera position) try having him pull back his left shoulder, creating a tilt and leading line to the shoulders. You also want to want a man to tilt his head towards the low side. An easy solution for this body position is to have a raised surface (4-8") for his left foot to rest upon and have him place his forearm on top of his knee.
I don't think the smile / smirk works here. It's in an in-between stage, I would suggest a no smile and an actual smile for comparison. The subjects don't always have to look happy, happy, joy, joy.
If the next button was buttoned..... guess what, no under shirt would show.
It looks as if you have some nice backlighting. The top of the shoulders are in good light, but the fron of the shirt is virtually absent of any detail. Remember to look at the light. Turning him anywhere from 30 to 90 degress to his right would probably given you some nice modeling light from the sun.
This is NOT a bad picture. Just some thoughts for the next time.