pixie2097:
I think you are worrying for no reason. If the 3rd party was responsible they will pay out when they receive the details. If they ask, just advise that the vehicle is jointly owned between yourself and your partner, with equal usage. I don't think they will be that bothered, as long as you were a named driver on your Insurance policy.
You should however, correct the details on your own Insurance, to make sure the Insurance and V5 details are matching. If you change the details, this may cause an adjustment in premium and they may charge an admin fee.
Huckster