Ian,
Here it is from an engineers point of view...
Although I am no longer at the forefront due to a career change I have been in many a situation where commercial pressure reared it's head, myself and all my colleagues never, and I mean 100% never succumned to commercial pressure. It's simple really, as long as you are right then you stand your ground and there can be no comeback.
As for carrying defects to the end of the day, yes it happens but these defects will be things that are not flight critical, I have been in situations where crews for whatever reason didn't want to do the last 2 sectors of the day and wanted to make the aircraft tech and I have asked them to carry the non critical defect to the end of days flying so it can be addressed later. On the other hand I have had a few crews who wanted to take an aircraft which I have deemed unairworthy and have had to persuade them otherwise, in one instance I consfiscated the log book from the flight deck!
Rest assured Ian, the reason why the UK and most of the leading countries in the world have very few accidents is because we as engineers and the professionalism of the flight crews will not under any circumstances take risks.
If you're looking for headline making stories do as a previous poster suggested and look into the security farce, it's the one reason why I left the day to day ritual of trying to get through security with my bottle of lucozade but I could with a tool box full of hammers, stanley knives and leathermans!!