I spent alot of time looking at these tensions and one day it hit me :

I went with my aunt to a doctor, while we there she told the doctor her hip was really painful, to which he replied "it's probably nothing", when she asked if he could take a look, a xray or something he replied : "you know miss I studied medecine 7 years, I think I know what am talking about"

Then I just thought, maybe this qa/engineering tension is just some inferiority complex. You know when you look at your average software tester, it's a guy who earn a quarter of what a engineer makes, doesn't own a degree or is studying, not someone a bachelor of science would respect in any ways. I still believe that is source of much tension, you can't receive a critic from someone you don't respect. I still haven't find a way to fix it, on the next project I asked to hire only retired teachers with computer skills, you know peoples who have a lifetime experience of dealing with arrogant pricks. I'll see how it goes.