Nobody hacked the game code, they took advantage of game features that may have not been intended to be used that way, but there none the less. This wasn't a big secret, heck there has been a post on these forums about how to do it. This could have been changed a long time ago. Players don't have any control over how the game is coded, but you can be sure that people smarter than me will always find ways to make the most of it. Like when someone figured out the degenerative interface incarnate power was borked, and people could zerg the hami without clearing the mitos. The dev's could have hot fixed it right away, but they didn't and people took advantage of it.
None of this is good, but players don't control the code.