I sold my 2006 Ford Escape about 2 weeks ago, privately on Facebook Marketplace. The car was in usable drivable condition, and the buyer (and her whole family of 5) test drove, and looked at the car before buying.
I documented the car was being sold "as is" in the Bill of Sale, and that there were no known problems.
The buyer messaged me 5 days later, saying an axel had broke while just driving down her neighborhood street and then told me it was because of rust. I didn't know about any rust problems so I contacted my mechanic and they assured me the axel could not have broken in the state they last saw it in, when it was last serviced - 2 months ago (when it also got new breaks for $1k) - especially from just driving down a neighborhood street.
The buyer then contacted me the next day saying the car failed inspection and demanded her money back under the Massachusetts Failed Inspection Law (stating if a car doesn't pass inspection within 7 days the full amount of money must be refunded.)
I asked her to provide the paperwork proving that the car had failed inspection. The paperwork she showed me stated the car failed inspection due to "steering & suspension" (due to the broken axel). Other than that the car passed everything and would have passed inspection if not for the broken axel - damaged by the buyer.
*What laws protect me in this situation? Is there anything that allows me to deny accepting back a, now damaged, car? Is there any legal action I should take?*