Btw, he seems a little 'lazy'. (Looking at his trash-damage. Ok, thats not boss, but it shows the player's will.)
On Teron his dps is not SO bad, but on Naj'entus, on Bloodboil, on Winterchill and maybe on Supremus, he should improve his dps heavily.
He use 1:1 as I see, but he has no haste so try to get some haste (like below) or try 3:2 rotation.
He should get some gear upgrade:
Bow-stiched leggings from Azgalor
Quickstriders mokassins from Anetheron (or better: Softstep Boots of Tracking from Teron)
Bindings os the lightning reflexes (crafted)
The blade of harbringers (from badges)
Crossbow of relentless strikes (from badges)
Enchants and gems are ok for him.
And, like the previous poster said: give some love to hunters.

(Agi totem, bloodlust, if u got enough shaman, drums of battle, Ferocious Inspiration, Trueshot Aura, etc.)
In our guild we got from 1 to 3 hunters in the raid, and the BM's (2) are almost always in the Top5. (If pet can dps (Not Archimonda), don't need to kill adds (like Anetheron), and dont need real burst dmg (Like Akama himself and RoS last phase.)