The question of sentience is a distraction, in my opinion. As you say, we can't even tell if other humans are sentient. And we are stymied by a lack of definiti

The question of sentience is a distraction, in my opinion. As you say, we can't even tell if other humans are sentient. And we are stymied by a lack of definition for sentience. The more important question for sentience of whatever definition is does it behave as if sentient? Likewise, for personhood, it's a distraction to speculate whether an AI feels like a person or whether its underlying technology is complicated enough to produce such feelings. Examine its behavior. If it acts like a person, then it's a candidate for personhood. For LaMDA, I would point to certain behavior as evidence against (most definitions of) sentience and personhood, and I think that Lemoine experienced a kind of pareidolia. That said, I find most of the arguments against LaMDA's sentience unconvincing per se as standalone arguments - particularly trust me, I have a PhD - even if I do accept the conclusion.