User blog comment:Mexican215/So who was satisfied with the last battle against the Reapers?/@comment-4967682-20130213023320/@comment-2250460-20130213053601

(I'm just going to answer the plotholes you mentioned)

1. Harbinger was already shown to be arrogant. He probably thought everything was dead considering the entire path to the beam was scorched. It was only by sheer plot armor that Anderson and Shepard survived. As to why he didn't shoot down the Normandy, Reaper IFF most likely.

2. It's been brought up before that we can't even be sure if it was a Destroyer, or one of those "mindless" Reaper platforms mentioned in the Codex. The Hades Cannon also probably required much power to use, which could also explain why it was so easy to take down.

3. Where was it mentioned that they moved it in less than an hour? As shown by the Original Control ending, the Citadel is capable of closing and moving by itself, so we don't know how fast it is capable of traveling. As to why they chose Earth, probably because that was one of the more controlled systems. All resistance their was pretty much crushed and it had a very large portion of the Reaper fleet, including Harbinger himself.

4. TIM had major Reaper upgrades. Simple as that.

5. Well considering that the beam was jamming everything, they probably thought one Destroyer was enough, considering most of their fleet was engaging Sword, they didn't exactly have time to prepare a battle strategy. Additionally, this is all a moot point because as shown by Harbingers arrival, the Reapers could easily send down a Capitol Shit to guard the beam in the event that the Destroyer was killed (which is exactly what happened in the game).

6. Because there is an off button they can just press. I'm sure if they could they would have done it.

7. They probably didn't expect anyone to reach the Citadel, and considering that it was mentioned by Anderson (and seen by the player) that the place was shifting and Changing, it probably wouldn't have helped much anyways.

8. Probably the same as the Conduit, but no one is complaining about that.