My own playthrough ended with
Rebecca dying.
I've examined the source code for the final quest/story, and one of three things will happen during the final warehouse fight:
- If you dodged Lily's dad's question earlier in the story (while visiting Lily's parents, he asks "Like what?" when Lily mentions there's a lot going on), and you yourself got shot, Paige will die.
- If you dodged Lily's dad's question, and you didn't get shot (where you had the "chance" to), Lily will die.
- If you didn't dodge Lily's dad's question, Rebecca will die.
The other two will have a chance to become part of your final harem, if you've made your other choices right.
In essence, the death of one of these three is unavoidable; the person who dies depends on your previous choices, and it all depends on two specific choices: whether you dodged Lily's dad's question about things going on, and whether or not you got shot during the break-in with Paige.