If JJ isn't going to heal Nate, what makes you think she's going to heal a complete stranger? I say he gets ran over, but they stuff him in the back seat to avoid leaving any tracks and even though he appears to be unconscious, he actually hears the group arguing about what they should do with him, whether JJ should heal him even if it's just a minor fix, etc. When the guy learns about her abilities, he pulls out a gun and forces her to do it. I mean, the guy's a thief already so who's to say things can't escalate, especially when he's hurt and drunk.

That's about the only way to get JJ to help him. Otherwise, good luck convincing her.