the remains if the citadel crash to Earth and Shep survives due to all the implants because I forgot that in the blue and green endings his/her body is destroyed as he/she controlls/merges with the Reapers. Kinda hard to fall back to Earth when you don't have a body. Also in the control ending the citadel doesn't even blow up. I don't really believe the indoctrination theory thing either (if it does turn out to be that I will shit bricks with the rest of the internet). I think the ending is just what it looks like. A rushed, confusing, uninspired pile of bullshit and nothing more.