Oh, back to the above:
Taking random numbers in a seemingly random sequence can result in enough random even if the generator is flawed. Generally in games where things happen in seemingly random order(most games) you can get away with a lot of RNG flawedness, a lot.
Never really paid much attention what the problem you fixed in RNG was, but the above can be part of a reason why an RNG bug isn't obvious. Since even randoming a solid stream of 1,2,3,4,5,6 and repeat wouldn't necessarily be obvious if the 'random' numbers were used in random enough order.
Oh, this is getting out of hand, this train of thought, I need to calm down now!