If serious, while I won't deny that I thought to myself, "
the Engineer is alive and ready to come after her? And really even gives a shit that much? I mean, at the same time, what the hell is the point of whining about this? I can just as easily come up with an explanation for it, and no, it's not simply tissue paper, or cardboard (perhaps wooden slats, but, honestly, as I said before, see: Hitchcock, the plausibles).
This kinda stuff just seems a little, I dunno, pointless to quibble about.
Why? The alien ship is of significantly superior construction to our own that, such that, in the event of a collision with one of ours, while ours would get completely destroyed, would just become (at least temporarily) inoperable. While inoperable, it was not so damaged as to become too difficult to escape from. Likewise, the Engineer, as a vastly superior being to ourselves, with a ridiculously huge and muscled up body, and extremely technologically advanced protective exoskeleton space suit was not knocked unconscious, and was not significantly injured. With the ridiculously advanced technology in his ship (that is capable of interstellar travel and planetary destruction), he was able to realize that there was another vehicle in the vicinity, belonging to the band of beings (whose planet he/his civilization, for some reason, seemed intent on destroying) that had just awoken him, and that one of the people from this band, who had just narrowly escaped him earlier, had escaped to it, and he wanted to find her and kill her because, for all he knows, she's going to radio for backup to the rest of her crew elsewhere on the planet to come and try to stop him/kjill him.
Boom. Not that difficult. Why let it ruin the movie?