Comment by zerd
I tried to use Valgrind to catch pretty much this exact bug 20 years ago, and it was nigh impossible. If you call any 3rd party code it'll have flag tens of thousands of false positives that you have to sift through. And that was on a small game engine, I can't imagine running it on millions of lines of code.
Again, you don't valgrind a whole game. You valgrind your unit tests. Even in 2004 when this game was released, and even in the game industry, unit testing was a routine thing. And this particular bug was in code very amenable to lightweight unit testing.