I have removed all gameplay audio from the video so you can hear my commentary on it a bit easier.
I do not die at all in this level, which is pretty nice.
Also sorry for the video for being in one corner, it was because the game is at maximum resolution, which was lower than my computer's resolution, resulting in the capture software putting black bars at the sides of the video.

































On The Pillar of autumn, When you get to the boneyard area, turn around and go to the part where you triggered the cutscene. The game should pause for a few seconds. This de-loads all elites in the boneyard area, and refreshes all ammo supplies.
In the room before the area with the 2 hunters, jumping on certain pipes, then crouch jumping onto the top, then running past will let you bypass the 2 white elites, and de-loads the hunters.
In the final room where you try and get on the mass drivers, you can bypass 2 of the elites in the room by crouch jumping onto the top and walking around the perimeter on a beam. Keep in mind that you have to kill 2 of them to make them retreat closer to the mass driver so you can actually access the blue robot arm in the corner directly across from the door. You can wait out in the gap between the platform and the stairs to avoid fire from the 2 remaining elites (although I recommend taking out the one with the fuel rod in case they spot you)
Ah screw this, this is a bit too long. Look up MythicTyrant on Youtube, he has some sweet walkthroughs that I consider better than people like NextGenTactics.
SPOILERSPOILERTHEYSPOILERALLSPOILERDIESPOILEREXCEPTSPOILERONESPOILER
I think when the city was being glassed it took down all of their shields, seeing as how it was similar to a grenade explosion. Also, she had taken her helmet off if I remember correctly, so that probably was a factor too.
Sorry, I tell myself this stuff to explain things I don't understand, I'm sure there's some explanation.
And, where the hell is Jun?!