The way the API was used incorrectly "worked", and the game didn't see the negative impact of it because it was "fixed away". And then the incorrect usage is used again on another game and doesn't get the "fixed away" benefit. And the same incorrect usage could happen over and over because "it works".

The next developer at that company that uses or references the crappy code for another project would still have the issue, but not get the benefit of the down-stream GPU vendor hacks to fix the buggy game.