"Note also that Hockham, one of Kao's original co-authors is (I hear) dead, otherwise he might have got a look in."
I believe there's a "no more than three winners" rule, so that wouldn't have been an option.
And as for any change of direction, I think new techniques have always been rewarded. An IBM trio got the prize for a kind of microscope (atomic force microscope?) some years ago. Sure, it's been used *since* to discover stuff, but the prize was just for getting the blinking thing working. Sometimes just being able to do the experiment is a greater triumph than the results.