Given the same installation fault appears to have existed on both engines, the probability of the same failure happening virtually simultaneously on both engines is not as remote as might be assumed. It appears the failures were somewhat progressive in nature rather than a clean break. An unlikely event compounded by failure to treat the initial failure as an emergency, which at the time it didn't appear to be. Cultural issues and poor CRM played their part too. One of those shoulda, coulda, woulda, gotcha situations.