Yes, their comment was extremely annoying, both in tone (whining) and content (TL;DR: “pls spoonfeed me basic reading comprehension”). If the mod simply removed the comment, or issued an official warning, it would be 100% warranted.
However, what the non-mod user is saying ITT about moderator abuse is still spot on. The mod in question answered to the whining in tone, tried to cover their own arse with content removal, and then went to whine in Mastodon about the events, or the fact that there’s transparency functionality in Lemmy (the mod log) against the exact same behaviour that they showed there.
So it’s a case where both sides were wrong but given their relative positions the mod being wrong is a bigger deal.