I am not saying it is the case, nor understand details of solution in depth to comment on it, but in analogy, this reads to me, like an yelling at person who figure out how to solve rubix cube puzzle steps, because once steps are known solution is simple.
No, other people have pointed this out, this should have been very easy to recognize as inefficient in the source code. More likely the code was written hastily and only tested against very small inputs, and then nobody ever actually tried to improve the famously long load times.