At the risk of greatly oversimplifying a complex and serious issue for the sake of lightening up a bit, let's not forget a rule of thumb that applies in most situations; if an engineer screws up fatally, it's the pilot who kisses his a**e goodbye, and if a pilot screws up fatally, it's the pilot who kisses his a**e goodbye.
An M3 MRO that I was once involved with decreed that the engineer who signed off an aircraft after work calling for a test flight should ride as the observer on the test flight, along with the company pilot. The ensuing outrage reverberated for months, centering around the declaration "Not my job, mate". They won, but I always felt the principle had a lot going for it. So far as pay negotiations went, it was a Pyrrhic victory for the engineers.