But that is what they say they do - at least when claiming that your site cannot be harmed by "actions outside your control."
And your experience may very well prove that fact - since your sites don't appear to have been penalized in spite of receiving the message (granted this may be a premature claim and may not bear out over time.)

From what I can see, the issue lies in the fact that they don't (for good reason) tell anyone how they determine if there's a tie to you.
So if a webmaster is indeed innocent, there's no way to demonstrate such.

But if your sites don't tank, then that should validate the claim that the message is simply informative, not a demonstration of an action taken.

Which would support my theory that sites only tank because they've benefited from the links before those identified as spam are discounted.
So the linkspam penalty isn't a penalty per se, but a re-ranking back to where the site would be with a blind eye to any links determined to be spam.