I find a 'forgetfullness' to renew ones' status as an examiner for over 6 weeks, as indicated in the OP, a bit hard to accept.
My Instructors' Rating requires a BFR as an Instructor every year - this happens in November and so far I've had no difficulty in remembering that, tho' I have to look at my logbook to pin the exact date down - which I tend to do about now.
Ironically this year I have a problem, the local Super Instructor authorised to re-test me is not available, nor is the next nearest one, albeit still some distance away, so unless I can find a solution, either travel a much greater distance, or pay for an examiner to travel an equally great distance to me, then my Instructor privileges will end until I can resolve the issue.
One of my present students is already lapsing into deep gloom at the thought that he might have to fly with someone else for a few months, until I can get myself re-qualified !
The point I'm making is that I'm already aware of a coming problem, not discovering it some 6 weeks later.
I'm not sure that the CAA, even if satisfied that the examiner still meets their requirements to be an examiner and is maybe re-qualified next week, can issue a licence against a skills test that was conducted during a period when he was not authorised. Logically, and from a commonsense point of view, why not, what's to say that he conducts a flight test whilst properly qualified but doesn't present the paperwork for some considerable time, is there a Statute of Limitations regarding the time that can expire between flying the test and sending the result to the CAA ?
A licence is not there to prove that you CAN fly (or examine ) it is only there to ALLOW you to, so commonsense says that if re-qualified then the examiner can present the same flight test results again.
But .... commonsense and the Law !!!