But it's pretty darn impossible for a new home owner to PROVE (and no I'm not an attorney...thankfully).
Yes, even if the OP has a case against the inspector (as in: NY allows it), it's still a long way to getting any money for the fix. I think we've seen the evidence that it was a pre-existing condition (so it was there when the inspection was done). More could be gathered from neighbors, or the sellers or the sellers' realtor, etc. That would establish the negligence of the inspector. That along with the fact that just about anybody, expert or not, could have reasonably been expected to see that defect (that's an important legal concept I'm not stating very well). But then there is the matter of the inspector's contract. Some of these guys use contracts that state they're only liable for damages up to the amount of their fee. Or that they're not liable for anything. It could say anything, and that might be the end of it, or the language could be challenged in court (generally contracts can't negate law). And the matter of the report: maybe he
did call it out and the OP missed it. And even if all that panned out: there is the matter of collecting. I had already asked the OP if his inspector had liability insurance. And he's kinda disappeared from this conversation.
So if the OP doesn't or can't pursue this course, we'll wish him well. But either way, I think the conversation is worth having because a lot of us (myself included) make assumptions about services and service contracts. We glaze over the fine print, assuming that we're going to get what we're paying for. And that's just not the case. The missed items of my inspection later cost me four figures. I never went after the guy because of all his fine print. The dollar amount was not too bad, but it was mostly pool-related. I now realize, especially because there was a pool involved, how much worse it could have been.
The lessons: read and understand contracts, especially when they involve very large ticket items (like a home and pool)! Have a separate, specialized pool inspection, by someone that knows what he's doing, before you buy a house with a pool.