However, little things like this is not really the bread and butter of being a good flying instructor. Knowing today's rules doesn't mean you know tomorrow's. As Genghis has show ;-)
Indeed, although the lack of single reference points really does not help.
The NPPL(M) air law syllabus on the NPPL website still refers to exemptions - when were they last used? - offhand I'd say about 1994; whilst BMAA's guide to airworthiness procedures hasn't been updated for 7 years now and still refers to "SLA"s. As other discussions have highlighted, there isn't a single place (ideally on the BMAA website) to show the microlight pilot recency requirements.
It's a sad state of affairs where an argument between greybeards on PPrune IS the best source of information on the regulations. That is how it is with microlight regulations at the moment.
G