Bottom line, the policy (a document issued to the insured driver/s) is your guide to the cover in effect and is what you would have to produce to the police in the event of an accident, or on demand, so I really wonder at the apparent fact that you have not, apparently even looked at it to see if you are covered. After all, it's your ass in a sling if your dad got it wrong, not his. You are supposed to make sure that you are insured before driving on the road.