Wow, I can't believe the RTB Mod Team didn't shift through the code a bit.
There is a position open for "reading every loving line of code in every mod ever submitted" if you'd like to apply. PM Ephialtes and make sure you reference this post. Code can be obfuscated too, it's pretty trivial to shift all the letters in a piece of code up 2 letters and then write a function that shifts it down and executes it, so it's not as easy as ctrl+f admin, you need to read every bit of the mod.
I should add that this post was intended to be a joke and you should not take it seriously or actually apply. As soon as RTB found out that the code was in there it was pulled from the site and Badspot also added it to the crapon list. Beyond spot checks and the file scanner I think most code just gets waived through, although you would need to ask a mod reviewer about their habits. There isn't really a better way to do it because of the amount of code submitted daily. An exploit could hide anywhere, even inside places you might not normally look, like maps. I suppose some simple exploits could be added to the scanner.