I take your point. But I think thats putting more thought into the question than needs be. This could be a perfect case of JARish making life more complicated than intended. Maybe the question should have said "leading edge flaps and slats IF FITTED".
I would agree that during cruse the slats and leading edge flaps IF FITTED are retracted. In this position however they become the leading edge and therefore must be heated by the anti-ice system, hot air is ducted down them whatever position it's in and whatever the stage of flight and therefore leading edge flaps and slats are anti iced.
Could of course be wrong ????
In JAR land who knows ????