He actually responded to just this question in the comments (and he's a very senior 10-year engineer, so it's plausible).

"I have various reasons to believe that the odds that I would have known about it are higher than those for most employees -- but it still wouldn't be a certainty. That said, the odds are good enough that I would be fairly surprised, and rather furious, to find out that such a thing had been happening without my knowledge."