Actually, given the apparently parlous state of Boeing's safety culture, it is more than possible that someone coming in from outside the industry will be best placed to instill the necessary change, as they will be asking some pretty searching questions of the current guardians of the processes and won't be easily fobbed off with any "we've always done it like this" answers.
A retired senior Naval Officer who has been brought up in the safety culture of nuclear submarines where there are two very key safety threads running through his daily life... the first the safe operation of the reactor power plant and the second the safe operation of the boat itself... may be the breath of fresh air that Boeing needs. There is the need to operate and be seen to operate any nuclear installation to the highest standards of safety because of the searching questions that always are asked if there is even the most insignificant incident. There's roughly the same number of souls on board one of the SSNs or SSBNs as there are on a short haul aircraft, and the consequences of a serious safety issue could easily be just as fatal.