Well the obvious answer is that a direct personal insult would have been “poster, you remind me of Robin Williams’ quote about living in Canada is like living over a meth lab”. As opposed to juxtaposing the entire quote by the poster to the “meth lab” quip. Is the post the poster?
If I remark that this thread is full of sound and fury, do I get a warning?
Just because you can find a way to make the insult more clear, doesn’t mean that the original way you wrote it wasn’t an insult. To use your own words, let’s just say it was an “indirect insult”. Those aren’t allowed either.
At this point, all I can say is: the house has been led to water. You can choose to continue insisting you were right, keep posting like that and risk getting a warning. Alternatively, you can learn from the situation and avoid similar posts in the future. Your choice.
Another rather obvious interpretation is “this post looks like a meth head wrote it”. Didn’t insult the poster! Just said his posts are meth head-like! I followed the rules!
That depends on whether your allusion is to Shakespeare or to Faulkner.
I don’t think so. Moderator Loach says upthread:
Anyway, the allusion was clearly Shakespeare - the words “full of” are the tip-off. So although I was only joking, not seriously asking, I guess I do have the answer now: YES. Calling posts “full of sound and fury” is potentially a warnable offense.
Don’t worry, I won’t do it. 
So, there’s explanations for how it could be an insult, and explanations for how it could not be an insult.
It’s fair to say, then, that the intent of the original post was ambiguous, yes? Well, the whole reason we have mod notes in the first place is for these sort of ambiguous situations. If it had been an unambiguous insult, he’d have been warned. Since it wasn’t clear whether he intended to be insulting or not, he was issued a note. This serves two purposes: it encourages the poster to be more clear in their intent, and it also discourages anyone who might have read the post as a personal insult from replying in kind.
Just to be clear, Miller, there are lots of times when posters who make obvious, unambiguous insults are given mod notes.
Upon first glance, I thought Grey was saying DerekMichaels00’s conjecture was like living over a meth lab, implying that it had a strong odor and could explode at any second. I didn’t know the context or that it was derived from Robin Williams, and I didn’t take it as a Canada vs US thing. I didn’t think it was a personal insult either, but saw that it could potentially lead to a flame war regardless. The moderator at least stepped in before that could happen.
When you leave out context and assume everybody’s in on the joke, it will backfire on you. Just sayin’.
I’ve always thought of America as more of a crackhouse, truth be told.