Well, if you read the thread in question, you'll see that our dear spammer friend grossly misstated the nature of the complaint in order to get the sort of replies "she" wanted. It appears that, as is usual in these things, reality is more complex than can be explained in a single paragraph. In particular, it appears that the posts were not flames, but posts forged in the name of the plaintiffs and sent from Google. Or at least that's what the plaintiffs are saying in public. Who knows what really happened. In any case, to abuse your metaphor, it's more like suing the guy who sold the spray paint.
In any case, yes, it's off-topic for every group it was posted to.
Followups were ALREADY set to nanau, in an attempt to flood that group with posts from people who don't know any better. I suspect they probably already knew about the problem.