The progression isn't particularly mind blowing, though. Once somebody notices a buffer overflow / register pollution of some sort, you note which area of memory it's executing and then reverse engineer how to modify that memory to execute particular instructions. I would expect a community like HN would consider this par for the course.

That said, what's impressive to me is the amount of time and energy individuals are willing to expend on this sort of thing. Speed runs in general, the sheer time investment and dedication. There's a sand mandala aspect to it all.