Aha, wasn't that argument more about that closed source software is more likely to hide stuff you don't agree with, than FOSS? Not necessarily that FOSS won't have any viruses or malware, but it's at least less likely. That was my take away, but long time ago I read the book admittedly, I might misremember or transformed it automagically over time.

You'd better read it again, because that claim does not figure in that text. You might mean that with more eyes on the code, more bugs are found, than with no eyes on the code. But that is not what you are saying here.