He would have needed to have 2 (it might be three) personal references on his application, and they must have known the person applying for PAL for a good number of years . Their names, phone number, what kind of relation, how long they’ve known you and their signature are on the application. IF you have a spouse they sign, if you have had a recent break up they ask to contact the ex so that contact info is expected. When those references are contacted if any concerns are raised (or questions answered in a way that is not acceptable) the application will be flagged for deeper scrutiny.