Yeah, I think the original statement wasn't worded exactly right. You can't check everything for a brain. There's a paper called "Welcoming Robots into the Moral Circle: A Defence of Ethical Behaviourism", which I think preserves the general idea of their comment. It says that if an AI is roughly performatively equivalent to other entities with significant moral status, then they deserve the same moral status by default. So if a robot walks up to me and seems to be exhibiting human like thoughts or emotions, it wouldn't be permissible to hit it for no reason, since it wouldn't be permissible to hit a human for no reason. If you don't know whether it is sentient, but it has the same behaviors as a sentient being, then that's enough reason to treat it as if it were sentient regardless of what's going on under the hood.