It's OK if the DMV accepts it and transfers the title to you.
Just make sure you don't pay him anything until that happens. Tell him you'll hand him the money at the DMV upon successful transfer of the title and see what he says about that.
If he's OK with that make damned sure you have insurance arranged on the car effective that day because the minute that title is transferred to you, it's your car and you are responsible for anything that happens to it (or anybody) from that minute forward.
If you end up in an uninsured accident, you're screwed.

