It's another exploit, different from the one revealed by bLiNdFoLdEd, his exploit looks like better than mine, but but i want you to know about mine =)
If you have any warlock in your raid, ask him to put a Demonic Gateway, which will pass by the middle of the room, to the position where the boss will go at the begining of the phase 2.
Ask to the warlock to have Glyph of Gateway Attunement (it will make it a lot easier).
And if you are warlock and your raid doesn't want you to take the glyph... you can buy Gateway Control Stone, to make it automatically activated only for yourself, which can be purchased by some vendor (just look on wowhead if you don't know about it)
Now the trick is to be to the opposite side of the the middle door, juste before the boss will grip you to the middle of the room.
If you do it right, you will pass by your door when he will grip everyone, it will result that you will be TPed, cancelling the 1st storm part (which hit you and drag you to the opposite side of the room to dps the boss faster).
Your really need to be close of your door at the beginning of phase 2, and make sure that nobody will drop a storm here.
I don't know about the fight mechanic in heroic, maybe you can use it too, if the battle remains the same?