Permabanned
Yes, because your bank loan probably isn't secured against the vehicle. As far as VW or whoever you bought the car from is concerned, you paid cash in full. V5 isn't proof of ownership anyway (not sure why you need your GF's name on it??? NCB has nothing to do with who owns the car?).
That doesn't really matter though... the lease company will have, most likely, financed the purchase.
He is still the one paying the finance agreement.
Even if it was purchased with VW finance... VW will have been paid cash for the car as brand-marked finance companies are under-written by other finance companies. Even if they have their own finance arm... it will be a separate company to mitigate risk, so the finance arm doesn't kill the production arm if the economy goes bonkers and no-one can pay their agreement off.
Heck... a company car could be "your" pride and joy if you love the car and your skillset will have been what got you the car in lieu / on top of your salary.