I figured anyone defending him was joking around as a troll but there appear to be 5 pages of it.
Not joking. You can call him a cheat. That's your perogative. But you're relying on the word of MI and lack of positive evidence to do so.
Please try doing what you said you would and run the next marathon to emulate Frank. Run the same time. Hit all the timing mats. Never get photographed taking an alternate means of transportation. Then do that at a dozen other marathons that aren't local to you and you have no idea where the mats or cameras are. And still never get caught obviously cheating.
And then I'll concede Frank could plausibly have cheated.