ChickenHouse
You aren't going to send the student on an International flight so I'm not sure what international regulations have got to do with it. Surely the international regs only apply once a licence has been received.
In the UK at least (and I suspect - the rest of Europe) an examiner doesn't declare you a pilot. The authorities do after all paperwork is completed and you receive a licence through the post.
My memory is that under EASA a student has to now carry a copy of their authorisation. Does that mean that the examiner has to sign it on behalf of / as the instructor? Or does the student get the authorisation before they leave home base?
I know that straight after the skills test (which I passed) I wasn't in a fit state to drive, never mind fly for several hours after completion with head spinning. A skills test is an intensive couple of hours...