Frankly, I just heard some good news:
- You're only in 50% (not counting those materials you paid for). And you have a hole filled with gunite, right? We've heard plenty of stories here that were far, far worse, including less construction and up to 100% paid.
- If I read correctly what you've written so far, you're at the gunite stage, which means a lot of the construction is still to come. Once you find a better contractor, I'm confident you'll end up with a better end result, since it won't be this incompetent contractor doing any more work. Many times, a disgruntled contractor has the right to finish the job, and that can turn into a real nightmare, because he's going to cut corners to recoup his profit, or just out of spite. Now, you'll be free to hire a better guy, and get a better pool, because this guy is out of your hair for good, without you having to use legal tactics to get rid of him. He's done you a favor, at least in that regard.
- His contract is a joke. That will work against him. In CA, a construction contract has to contain many components, or it is virtually null and void. And it is on the contractor to furnish a proper contract, because he is the expert (there's a legal term for this, which I forget). So a thin contract will contain a lot less provisions, or none, that would protect the contractor, and that's good. If the contract doesn't contain specific language for termination, then there are no implied termination provisions, which means any decent judge will have to side with you if any termination terms are in dispute. All good, assuming TX treats contracts like CA does.
- It sounds like he may still be in business, either with the pool company or the other company, or both. This is FANTASTIC if true. That means he has assets, and a reason to protect them. Which is just more leverage for you. You'll be negotiating from a position of strength, instead of trying to squeeze blood from a stone.
- His language about supplying a spreadsheet of the financials is also good news, because that would mean my assumption that he was bankrupt and/or broke and/or going out of business might not be the case. Which means he's got something to lose, and assets that can be seized if he owes you money (which he probably does). It sounds like he's trying to back out of the contract with a minimal loss to him, but a decent lawyer (yours) will make mince meat out of that. He's breeched the contract (which provides no terms for termination), and that too places you in a position of strength during negotiations (or with the judge).
Based on all this, a best case scenario might be that he could be liable for the entire 50% you've paid. That may not be likely, but breeching a contract is a serious matter that has way more repercussions than the contractor getting to state what is paid and owed and then trotting along on his merry way. What he did is highly illegal (at least in CA), and that, too, could be a good thing in terms of leverage. Now a more likely scenario, and what would be fair, is for a third party to determine the value of the work done to date, and for the judge (or the two attorneys) to then do the math to make you whole. In other words, you pay for the industry standard value of the work done to date, minus some sort of penalty for his breech and leaving you in the lurch, and then the judge rules he must pay you the balance (the difference between what he collected and what he did). He should also pay for an expert to assess the work completed to ascertain its worthiness (perhaps some core sample analysis of the shell to confirm it was done property, and a plumbing test, etc), all of which he would pay for. Along with all your attorney fees too.
I'm making a lot of assumptions, but as I said, I heard a lot of potential for, well, maybe not an ideal outcome, but certainly one not as bad as I was picturing. I truly hope that is the case.
Put your energy into finding a good attorney, and a great contractor, and then let them do their jobs. Then let it go and let it resolve itself while you refocus on what is ultimately way more important: you, your family and your peace of mind. Best of luck.