actually, yes he did. he is an owner as he completed a purchase of the vehicle and until his "after the sale" actions that sale was legal. it is the buyers responsibility to assign the title to their name, not the sellers in a non dealer auto sale. any attempt to make the douche that sold him the vehicle disappear and only use the original owner as the seller is just as illegal as what is going on now. "Joe" sold the vehicle legally and in good faith, you can't touch him. Although he is probably a person i would want on my side through this whole ordeal as he can vouch for the sale and probably will save the new owner in the end if this has to go to court (which i doubt it will).
We all seem to be forgetting that there is a registered legal document involved now that shows the illegality of the whole thing. That is not going to go away regardless of what private individuals decide to do. You have a totally screwed up title with mileage changed, signatures forged and an owner missing. You have a vehicle with a tampered odometer. This is not an easy fix if done legally.