Unless something like a mind controll device was used on them, but that would just be stupid. I could understand hives against hives, but not genetic mutation of an alien (Predaliens) fighting against it's hive and for it's host.
Let's think about it like this.
If you and a group of friends went into forest, and 3 got face hugged, would you let the creatures that tore out of your friends chests team up with you? No, you'd be angered and scared. You would fight them, or run away.
Now imagine that same scene, but only you are predators, and allowing a predalien to exist could lead your clan to banish you. Would you let them live, let alone side with you?
This is your life. Consumer. Animal. Hypocrite. Worthless.