I suspect that "industry-wide bug" in this context is simply Cisco pointing out to their customer base that this isn't Cisco's fault and please don't blame Cisco.
Neither of the first two nor anything else ending in a question mark unless you're really asking a question.
Not #3 because you're still being coy.
I'd suggest #4 or #5 when dealing with peers but they aren't interchangeable, they mean different things.
Save #6 for when you're giving tons of feedback to a junior.
If you're worried about being perceived as harsh or unfriendly, remember you can still be super friendly in the chatter on either side of the review session.