Yes, yes, I know, hear me out.
The so-called "Indoctrination Theory" holds in theory that Harbinger intruded Shepard's conscious mind via a seemingly advanced and overly elaborate indoctrination phase. Meaning; while our protagonist lied down in dust and rubble and blood, events occurring post "harbinger shot", as we will refer to for the sake of this blog, only exist in Cmmdr. Sheepherder's head, with Mr. Harper symbolizing Harby's Control and David Anderson representing Sheppy's subconscious fortitude (i.e. Destroy).
Now, taking all this in mind, where everything following the sudden white fade-in screen including Marauder Shields is Harbinger indoctrinating Shepard, we could very well conclude that Hammer Team failed to reach the beacon, and Adm. Anderson literally called for a full retreat. I.e. meaning that everything and everyone surrounding the teleportation beam is either stable or rapidly degrading. Hammer Team was obliterated, Anderson's forces fall back, Harbinger is converting Sheploo and the Battle for Earth rages still, undecided.
Considering everything I've written... our fight continues unhindered... one can only ask;
What of Earth?