They were present for the kill and saved to the Raid ID. It doesn’t matter what you complain about, how you slant it, what you say to tear them down. Performance doesn’t matter, loot rolls don’t matter.
They are saved to the Raid ID, so they have every right to finish it. You can continue to stomp your feet about it, but you’ve been given the answer, no matter how much you don’t like it.
YOU don’t have the right to steal THEIR kills, either. You do not own the Raid ID, neither does your guild. It belongs to everybody who is saved, including the ones you don’t like.
Yes, now you’re getting it! It’s ok for them to finish any Raid ID they are saved to.