Feel bad, but not guilty
The last car I sold without my name on it was to a member here. Now bear in mind Jackie is a great guy and got it figured out. And also the previous owner (executor) was a square egg but it could have went bad.
When I realized there was a title issue my last conversation was I would come get it from his residency in NC, pay him the full amount, and reimburse him his troubles. But it got worked out. And I said never again....
Honestly OP you jumped the title. He's got you if he wants to pick a fight. Just be aware of that and otherwise I hope you get it sorted out...
JW