The Culture Channel

My guess is that the fact that no one but the two authors and the mod had access to the evidence made it look like a case of "he said/she said" to many people rather than something clear-cut and proven (when apparently it was proven, but not publicly), so people reacted according to what their previous experience with plagiarism claims was (hence, either completely believing it because their last fandom had a serial plagiarist who pulled this kind of thing all the time right down to protestations of innocence and fake apologies, or going "well, the last supposed case of plagiarism in my previous fandom was someone who'd written a pirate AU claiming that any and all AUs where the characters were pirates was plagiarizing her; how do we know it wasn't just common h/c tropes the author only thought were copied from her?").