You know I hadn't thought of this. I had missed the fact that so much time had passed. I think that in Alien the burster arrive within 24 hours or so and stupidly within ten minutes in AVP (the most stunningly stupid and avoidable plot hole). Shaw obviously had time to gather food, oxygen, tools etc. Was she able to figure out how to re attach David's head in that time as well? Interesting indeed!
Very interesting. I always thought Shaw's comments about "only death awaits" referred to the other Pyramids and the bio-weapons they housed.
Given that it took them a week to take off from LV-223, a lot could have taken place you're right. However, I doubt Shaw and David were aware of the Deacon's existence. Concept art depicted the Deacon climbing out of the crashed life boat as Shaw and David left the moon's atmosphere.
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