We know three things about the officer in this picture.
1) He has never fired that rifle with those sights before. We know this because if he had, he would have fixed the impossible-to-use setup that he has there.
2) Even though he's never used those sights with that gun before, he's trusting his life and the lives of those around him to its accuracy -- and to his ability to use that setup accurately under stress. We know this because he's using it during an actual encounter where lives are at stake.
3) Neither his immediate supervisor nor any of his squad mates know how to use that type of sight, either. We know this because if they did, they would have corrected his error.