Testing danger!

I was sat in the waiting room at my local garage today and had some thoughts about testing and where we would be if people didnt take effort to ensure accurate testing. What would it be like if you had your MOT done then two hours later died in a crash cause by your brakes failing. In response the garage said "Well it all seemed to be passing so we just passed it only missed a few bits out." 

I think the main value in testing comes from doing the best job that you can to ensure quality and covering as many areas as you can in the time given. Then taking the results that you have and formulating a recommendation to proceed or not to proceed.