Eli entered Oskars flat when he was being a prick to her...without being invited. It's not a nice thing to think about, but what do you think might have happened if Oskar had been a bigger prick than he was at the time? Would Eli have bled more and more and more finally collapsing, puddling to the ground like a wet dishrag? Would she have exploded? Like I said, not nice to think about, but vampires usually aren't.
http://let-the-right-one-in.com/fancontent/content/eli-about-bleed


