Sometimes they think they will get you in finance or in addons and if you don't let them, then yes it's possible to destroy them in relation to a normal transaction. They often get paid on incentives or other structures too so they could be getting destroyed on a single sale. Last car I bought I negotiated the price and then the finance guy came over and hadn't yet understood that I already had financing ready at a super low rate. So they thought they would get me there but I refused to let them even try to run my credit.

It's certainly possible they made no money on the sale itself for a variety of reasons.

They love getting you on financing, but will never count on it if it’s not already on the offer.

You might have got them down to net zero on this on - I have no idea. But the vast majority of people who think they did, didn’t. Just part of the game.

There are pretty reliable ways to get a good/better deal , but they still make a bit of money. And you’ll usually compromise something too.