I got really curious trying to find stuff and I found this. There's actually 2 different ways to go out of bounds, this way is the hardest way. If you go to the very top of the wall and go under the blue line you go out of bounds more consistent.

There is a different way to do this skip that i have found and its faster too although it may only be possible due to me playing on the wii though. So all you do is you go to the end of the corridor where the fight is happening and wallcrawl threw the blue door its really easy but i dont know if it is possible on ps3 or xbox.