Yeah, you were right, it spits out an 8002F14E error at 73%. From extensive searching, this seems related to the blu-ray drive or the FFC cable/connection. Seeing as I replaced the blu-ray FFC connector on the mobo, I think there's either some flux remaining or a bad solder join. I'll take it into work and examine the soldering.
After I managed to get it into recovery mode, it would still shutdown after a few seconds unless it was in recovery mode. I tried several times to downgrade using the E3, but it would not work.