Ah, I remember those bodies now. But this is what bugs me still. Maybe I am dumb, but the movie sort of portrayed that the tomb was sealed and that it had only one entrance which also worked as an exit. We didn't see nor hear anyone mention otherwise. In that holographic sequence, lots of Engineers ran into the tomb, then the door was sealed and beheaded the last Engineer. But their bodies are found at a place different from the tomb's interior. So, how did they get out of it?