Oh, okay, so now that glitch developed a little bit since S2?
Usually she would just disappear as always, but when you killed her, she would drop her stuff AND die all the way. We already know that when you kill a monster, they have to be on their backs and flashing, getting ready to disappear.
My guess is that she died, yeah, but she coupled it with yet another glitch, where you kill something, and they're at ground level, but still in the mid-air falling animation. It's a horrible glitch that stifles progress unless the Host leaves, I think. Or the one who's lagging. Or something. I don't know much about the exact way to fix it. Hope this post makes some sense.
Pinkie Pool's archnemesis: Oatmeal.