Crikey!
Caveat emptor!
I would've done exactly the same.
If you'd gone along with his 'cunning plan', a few months down the track there would be a distinct possibility that someone would tap you on the shoulder to tell you that the truck was theirs; and is stolen property.

And I'm sure you don't want to chance not only losing your money; but quite possibly facing a charge of receiving stolen property!

Yep; getting rid of him was a wise move on your part alright!