I don't think they shut down... Maybe they just remember the mistake... forever.
If they're hit by a dracon ray, they must show them dying, because, remember, the Yeerks don't know they exist! If they have a hologram generator, they probably also have a shelter generator who can protect them. And even without that, they're probably strong enough to not be destroyed by a ray from a small dracon beam. Indestructible, I don't think so. But strong enough to resist though time...