From my experience, which is a very small intersection of a software validation background combined with work in the gaming industry, labs like GLI sprung up from demand. Gaming laws were written to require independent verification from the start which seems smart.
That said, labs like GLI don't really comb the entire code for bugs. They're looking for obvious things like backdoors, flaws in random number generation, payout table problems...blatant things that would make a machine fail against the player.
Bugs still do happen. Google for "$42 million jackpot denied". You'll find multiple instances over the years, and you'll also quickly see that the actual amount in question is almost always $42,949,762.95.
That said, labs like GLI don't really comb the entire code for bugs. They're looking for obvious things like backdoors, flaws in random number generation, payout table problems...blatant things that would make a machine fail against the player.
Bugs still do happen. Google for "$42 million jackpot denied". You'll find multiple instances over the years, and you'll also quickly see that the actual amount in question is almost always $42,949,762.95.
Why is that number special? =)