Otto Mossberg (owm88@hotmail.com) writes:
It was thought that the Covies had managed to reseal the flood, behind the door Keyes opened in 343 Guilty Spark. and in effect Keyes made the mistake of re-releasing the flood, while searching for a weapons cache. but, in the same cinematic, Keyes get a radio transmission from another group of marines, apparently being attacked by flood. so Keyes couldn't have just re-released them by opening the door. and if flood were already out, why had the Covies sealed that door?
Why indeed. Unnecessarily locking a door is not something I would be immediately concerned with if already under attack by a parasitic life form.