Hi there,
I realize I'm about 5 years late to this discussion. But I looked through this thread and don't recall seeing a Henry about what I will call "colonist extraction theory". It goes as follows: you see Bishop performing a detailed dissection on the parasite in the colonists' lab. Wetland Yutani kept many things under raps when it came to their engagement with the derelict space craft on LV 426. In all likelihood here would have been a number of eggs or post-natal xenomorphs in their infancy on ice. Keeping in mind the colonists were there already for decades setting up he atmosphere processors (furthermore, we are not told when they engaged the ship where Kane was overtaken) so one could easily assume that aside from making the planet breathable, they were consumed with researching the xenomorphs' DNA structure (since they worked for the company) either for their own benefit or their own. It could be that if intent was in fact for the bio-weapons division...but due to their radio silence with the colony and the company hub, Burke was dispatched as a contingency plan to somehow get the animal specimens past WCC quarantine. Here comes the colonists extraction theory:
Under Burke's instruction or by his own internal, company-mandated directives, Bishop uncovered what the colonists had placed into cryogenic stasis or some kind of incubator and possibly had Farro and Spunkmeyer quickly bring it back to the Sulaco with a measure of subterfuge and plant it inconspicuously on the Sulace as a part of some company driven contingency plan for getting the species off the planet and onto a company ship (of course for this possible part of the scenario, it would depend on e elapsed time between the APC's initial landing on LV 426 and the marines' engagement with Newt and the rest of the aliens, as well as the radio transmissions between Apone/Hicks and Farro/Spunkmeyer-as it would be a broken up transmission from space). Another option is that Bishop used the "working transmitter from the APC" (if you'll recall Hudson's comment after Farro crashes that it, the transmitter for remote controlling the dropship, was on the APC) and remote controlled the other drop-ship while the marines did their thing, many hours likely went by, and did the whole thing by himself--having got the viable egg onto the Sulaco, perhaps delivering it to a company research team/or android that travelled with the marines to LV 426 for this very contingency plan. Or maybe he simply remote piloted the ship down to surface, went up to stash the egg, then returned to research the specimens in the colony labs. (Perhaps when Bishop says he can't by mission of action harm a human, this is just a cover up for all of his company programmed sub routines).
One must, in this case, have faith that the colonists had a sincere interest in he xenomorphs, though they were not warned about gem by Burke, who had knowledge they were there, and had first dibs on and monetary reward--perhaps it was this animosity that led to Burke's neglect to warn he colonists of the threat. At any rate, just consider this: how did Bishop get the face-hugger in the first place? This was quite early in the films action packed events. Bishop wasn't sent down with he other marines to engage but somehow got his hands on this parasite... How? No one has asked as far as I can tell, perhaps this s the key to unravel the whole mystery. Lets theorize that the colonists had a wide variety of specimens in their labs, somehow they got out of control and lead to their demise, as the xenomorphs are mostly uncontainable. Ergo, colonists extracted the eggs and specimens, Bishop reaped where they had sown as well as their benefits. Just a theory.
Thanks.