Do you think a cheetah knows anything about speed records? Who's the fastest cheetah? It doesn't matter who the fastest cheetah was because cheetahs don't keep records. And that chicken you ate -- Did someone record how much it suffered? Then it doesn't matter how much it suffered. The point is, if you are willing to kill something -- to erase its state of mind (the majority of its 'record') from existence -- then you're actively making its suffering irrelevant. If someone starts my house on fire, that fact becomes irrelevant when they detonate a nuclear explosion on it.

>Just because something bad that happened is in the past, doesn't make it OK that it happened in the first place.

It is ok that it happened. It's ok that everything in the past happened. It's not ok to forget that it happened, or to fail to learn from it. But killing something is a great big "fuck you" to that thing's memory and learning facilities, so there's quite a lot of hypocrisy wrapped up in thinking that killing something is ok if it didn't suffer.

Suffering and death are bad for reasons. Those reasons provide proportionality to ethical evaluations.