Refunding cars?

Level 1
4 days after the sale of a car on here, the buyer wants a refund. He claims it falls under the lemon law, which doesn't hold on private sales in Arizona, and he claims I was not upfront with him about all the leaks. Yes to his first question in our messages I said no leaks, assuming he meant fluids. But as I sat with him on the test drive, I told him it needed a freon charge about once a month, and that we had not put any in since last Christmas.
I also disclosed that only the drivers window was able to go down and up. I also disclosed that the gas cap caused the check engine light to come on or go off, and he himself demonstrated that it did go off after jiggling it.
Beyond this, to my knowledge, the car is/was totally mechanically sound in all other ways. And he test drove it, looked under the hood, checked the oil etc. He offered 1000$ and we accepted it. It was my dad's car legally, halfway given to me under the pretense that I would learn how to drive though I haven't yet got even a permit so it wasn't in my name, nor was I insured on it. My dad decided to sell it, and I suggested I'd help get it sold by putting up on offerup. Offerup did actually get the most activity, but most callers were flakes on their appointments.
My dad came out, gave him the title and the keys, and the man gave the money and we thought that was that.
Now he wants a refund claiming he'll get a lawyer and such. He came to our house to buy it, which is a concern in itself now.
Are not all private car sales sold as is? And is it the buyers responsibility to go through the car? I'm no mechanic, the car drove smoothly when I rode in it, and I thought for 1k, a functional car not dripping fluids and not having any major body/paint problems was on the low side and a deal, considering all those on Craigslist were listed as higher for the same make and year.

Should I feel oblidged to continue communications at this point? The previous legal owner of the car, being my dad, isn't even in town right now. I don't really know what to tell this buyer. I almost feel inclined to ask the police's advice.
Community Helper
I would report the user to Offerup and then go to the police for advice. Everything was done on your part as far as telling him everything that you knew was wrong with it from what I can tell. You could try telling him that the sale is considered final due to it being a private sale and not a dealership and he should have had a mechanic come with him to check it out more thoroughly.
Community Helper
Welcome to the Community forums
Seems like the buyer is looking for a "Free" vehicle. Does AZ have Buy here's? They are even considered "as is" you get what you see...
Would take the suggestions of @aidenholley and hopefully since they have your address (not recommended) would file a "restraining order" if needed.