Hey jon - you want that Grumman should have designed it so both sides will fail simultaneously?
I'm not privy to TT, cycles, or inspection practices on this G73 - but a gross fatigue indication, discovered within a few days of the accident, sounds very much like a red flag that should have been found LONG ago.
FWIW - The early Martin 202 had a fatigue trap built into the lower sparcap, and an early fatal crash was due to it breaking. It was designed within a year or two of the G73, and several years before the Comet. There was not nearly the fatigue awareness in the design community that we have today. Let's just say the Mallard was more successful in this regard than either the Comet or the 202.