User blog comment:Aeratus/Guide to the Adam Jensen Clone Theory/@comment-29940722-20161114170435/@comment-30128802-20161115065037

I would think that the actual extraction process itself does not require willing participation or even that the subject be concious during the process. Given that Adam was at the bottom of the wreckage for days, I think it's likely that Adam was essentially "dead" after Panchaea. If this is true, then the memory extraction was performed on Adam's clinically dead body.

The memory extraction process isn't fully explained. However, there are many examples of neural interface technology (for example the Hyron project). It seems like neurological technology is advanced enough to cover all sorts of possibilities, including extraction of memory from a deceased body. Adam didn't wake up in Alaska until one year after the Aug incident. I think this period is long enough for all sorts of experimentation.