A bit of old fashioned trust? Wow, what an amazing concept, leaving the responsibility with the individual rather than the nanny state.
It is the responsibility of the pilot to have the correct paperwork. If they fly without a medical then they are illegal. Makes little difference who you send it to!
Modelman, you will invariably end up being charged by your own Dr for the NPPL declaration. I see you are in Daventry, give Frank Voeten a call for a Class 2. He is a superb AME and really friendly guy as well as charging a very fair rate for his services. He is at the Danetree on London Rd. If you are a Flyer Subscriber you get 10% discount as well!!