The difference, I think, is that Apple KNOWS about certain problems, e.g. Trackpad. If there's no water damage, then it's clearly a manufacturing defect. In OPs case, they thought he was lying because they'd never seen that issue happen without accidental damage.
A similar thing happened with an HP laptop I owned. They had problems with hinges breaking for no reason other than poor design. I searched online and found a bunch of people had the problem and some got it replaced as a manufacturing defect. I tried for months to get HP to do something about it. Finally I went to my boss who at the time was connected with some HP big shot. Using that leverage is the only way I've ever gotten HP to fix a single thing.
We're blessed with lots of old and failing HP kit which is slowly being swapped out for Supermicro stuff so every time something goes pop, they get on the phone and screw the warranty as hard as possible then sell the warranty bits as new on ebay and scrap the chassis.
This is our operations team's way of issuing karma for years of pain if that's any consolation :)
