Feel bad, but not guilty

I sold my Dart last week, had it two years never drove it except off the transport and into the yard.
An interested local buyer came over, as questions, looked over the car and parts that went with it, cranked to motor, listened to it, reved to motor, depressed the clutch pedal to listened to the T bearing(I guess), looked at the trunk, under the car, asked questions, shifted the gears (4 speed). T stat was weeping and the brakes needed bleeding
We reach a deal I gave Him the title, He paid with cash and then he loaded up the parts and the car had just enough brakes to hold it, backed it out and drove it up on the trailer.
Then 2 days later He contacts me on facebook, he bled the brakes and drove it around for a while, can back to his house and shut it off, went to crank it and the motor was locked up, he also said the trans was grinding going into 4 gear, damm!
The day after that he says someone printed a name on the front of the title and he couldn't register the car, he said it was worthless.
I asked him to make copies of the title and give me one Cali plate and I that I knew someone in the tag office that could probably get it straightened out for him, crickets!
I feel bad, but I did not know the motor was gonna go out, who knows if he horsed it around or whatever.
Feel bad, but not guilty.