However, there is nothing to stop one of the flights being used as the "training flight." I certainly would have no issue with that, it's just that the logbook would need to be annotated to meet the requirements.
There you go again, what annotation? What requirements?
ANY flight of 1hr or greater with an Instructor counts as the flight towards the revalidation requirements. When are you going to get it into your head that their is
no requirement to write anything in the pilots logbook apart from your signature and CAA reference number to confirm that a dual flight took place.
To answer machJump CORRECTLY, yes any of the DUAL sessions from the night rating as long as they were greater than 1hr would count towards revalidation.
I sign every students log book that carries my name as pilot in command. If you do a flight with an Instructor that is a dual flight make sure you ask that they sign. As an examiner I check the logbook for the last dual flight greater than 1hr, that the required number of hours have been flown for revalidation by experience and that the licence is valid. I then sign in the correct space and send the SRG1119 to the CAA.