BTW - the 'Examiner cannot examine anyone to whom he/she has given instruction in the last 10 hours' thing is incorrect. A UK/FE(PPL)A may not examine anyone to whom he/she has given any flight instruction for the same class/type.
The only instruction an Examiner may have given an applicant for the PPL who he/she is examining is a progress check or safety check during the PPL course.
Any Flight Instructor is required to provide a full flight instruction service to the client. Not just in the air but also, much to the chagrin of low-quality hours-building Wannabees, in theoretical sujects as well.