Below are linked photos of "Mark Owen's" HK416 in his book
No Easy Day that he presumably used in the OBL raid.
It does not appear to have any BUIS installed, though it does have an aiming laser attached in addition to the EOTech/flip-up magnifier.
http://spartanat.files.wordpress.com...owens-guns.jpg
http://spartanat.files.wordpress.com...owen.jpg?w=584
Note to mods: I have linked rather than posted these photos because I'm not sure about copyright issues, though it would appear that the linked site had permission to post these, since they do not appear to scanned from the printed media.