I've read the deleted comments and you are being rude in there. Whether they should have been deleted for derailment is another matter, but taking an aside to call someone childish is most certainly rude, we don't need to dwell on these other matters to understand that. Taking offense at being told to stop overthinking
may be valid, but in general I would say it's fine.
We do delete comments, historically, for derailment. The fact is that only mods can see deleted messages, so you just... don't see them. It happens with some regularity.
So, the point of contention comes down to whether this is actually derailment. Insofar as I can tell, Oblivion deemed his own comments as derailment and your replies to them as part of that, which is a valid way to look at things. The deleted string of comments begins with Oblivion discussing access to a book which hampered evidence gathering, which is derailing (although harmless enough to stay, they add context).
I think your comment was basically fine, or at least the first one was, but that Oblivion's was mildly derailing. You shouldn't be in trouble for derailing, although this behavior that has come after is not welcome and is, in my opinion, in violation of our basic rules of decency and politeness.
TL;DR My opinion in your case is that you need to be more polite to others, but also that the comments probably didn't need to be deleted (although I think it's a borderline case). I don't think this is worth getting in such a fuss over, though, this seems to be an egregiously petty case.
Regarding this.
I've been of the opinion that GodlyCharmander needed a longer ban duration due to the multiple sockpuppeting instances down those years. It becomes unreasonable to evaluate a ban by its duration when there is activity from the banned user via alt accounts. Had it just been that original offense, I would have been fine with an unban years ago.
That said. I suggested that GodlyCharmander return to appeal his ban one year after his last sockpuppet was blocked. We, since then, have not detected another sockpuppet of his in the interim time- someone is free to correct me on that, I am not omniscient yet. In light of that, I would approve of an unban request. A year of no further infractions, albeit preceded by multiple years of consistent infractions, is enough for me to extend the chance to return. This is conditional on no further socks being found out.
