I totally get your point, and it's a good one, but it's really hard to tell in this picture. In my opinion, it appears that his index finger is curled alongside the other side of the trigger guard.
Like I said, it's a bad picture, but if his finger was on the trigger wouldn't we see it poking through the trigger guard?
Obviously, the curled index finger is not as good of a safety practice as an extended index finger for just this reason. If his index finger were extended then everyone could see that his finger was not on the trigger from almost any angle.
Caption this Meme
