70, are you guys kidding? Who would ride in a plane flown geriatrics?
I would. If he meets all the other requirements to keep his license, including the draconian first-class medical (which is already excessively stringent), I have no problem at all with him flying at age 70 (or even 80). Age isn't important. Health, experience, and attitude (not necessarily in that order) are all very important.
It saddens me that there are pilots so unhappy with their jobs that they cannot wait to retire. And it saddens me even more to think that arbitrary age limits destroy the careers of pilots who happen to love flying. Age is not a barrier to being a competent pilot, so why should someone who lives to fly be forced to abandon it all and sit watching television for the rest of his life just because he's past a certain age?