You say it like that doesn't happen. It does not matter in the least what profession it is in, there is incompetence. The lettering on my tailgate has now been done three times due to it. The same guy gouged part of the plastic trim trying to fix my seat cover. That same guy also couldn't put the foam back on correctly. We have all heard horror stories about mechanics who seemingly forgot to put the oil back. Don't get me wrong, I am not saying it happens 10% of the time or any great number but it does indeed happen. It doesn't really suck til its you that has to be that one.