No, just no. No one with any sort of a clue ever argued these issues cannot happen with Free Software.
No, they haven't made that claim in so many words. But they've sure as hell implied it for years now. That's the whole line of thought that Raymond's statement (quoted in TFS) is based on.
Huh? The quote is "given enough eyeballs, all bugs are shallow." That's a clear admission that open software, like all other software, contains bugs; that's why you want the many eyeballs. Any claim otherwise is a symptom of not understanding plain English. Eric's whole point was that the bugs in open software will be found and fixed faster than the bugs in other software, due to the population of interested people who will study it, looking for the bugs. Nothing in that quote implies (to anyone with reasonable understanding of English and basic logic) that open software doesn't have bugs. I expect Eric would just chuckle at the very idea of software without bugs.
(Actually, someone near him should ask him. Tell us whether he chuckles, or snickers, or just gets a sad look on his face. Or maybe he'll say "Well, there is a conjecture that bug-free software exists, but in has never been observed in the field by reliable observers."
A much more useful conclusion from this story (if you're serious about computer security) is that this bug has been found and fixed in OpenSSL, but with its proprietary competitors, we have no way of knowing what horrible exploits they may be hiding. And you'd be a dummy to think they don't have exploits; every chunk of security-related software has exploits. The meaningful question is whether they can be found and fixed by the people using the software. If not, you'd be a fool to use that software.