Even granting your premise that a Google employee could leak the gag order undetectably (and I'm not confident about that, since the universe of people to investigate would be relatively small), there would still be serious repercussions to deal with.
At bottom, there's someone at Google in charge of overseeing the gag order. If the gag order leaks and they can't figure out who's responsible, I'm pretty sure they end up going to jail - if only because a court would have a hard time telling the difference between genuinely not being able to find the leaker and stonewalling / implementing a cover-up.
I'm less cynical. I don't think they can prosecute someone without evidence beyond reasonable doubt. Every single google employee who has to act on the order and be gagged by it has to see the order and verify its authenticity or else their actions would be illegal. "it must be one of these 50 google employees" might well be completely true, but not enough to prosecute any one of them.
At bottom, there's someone at Google in charge of overseeing the gag order. If the gag order leaks and they can't figure out who's responsible, I'm pretty sure they end up going to jail - if only because a court would have a hard time telling the difference between genuinely not being able to find the leaker and stonewalling / implementing a cover-up.