I disagree. Numbers are irrelevant. The GP's contention was that if non-human animals think, then maybe they're making a conscious decision to consume the flesh

I disagree. Numbers are irrelevant. The GP's contention was that if non-human animals think, then maybe they're making a conscious decision to consume the flesh of another creature. We, buying meat at the store, are radically disconnected from the life we're consuming. Killing the animal you're eating is a visceral experience — literally, there are viscera involved. I submit that we would be much less sanguine about meat if we were more involved in its consumption than, "purchase, remove shrink-wrap, heat."