I disagree with your characterization of that the mods don't know what's going on.
The moderators seem to be making it quite clear: they do know what is going on and the onus is not on them to prove it, only to notify actions have been taken in response. https://www.reddit.com/r/Seattle/comments/1xhf6qp/archivetod...
This attitude is extended when someone else asks a question about evidence, instead of replying to the question, the moderator sarcastically calls out the commentor for posting in the sub for the first time: https://www.reddit.com/r/Seattle/comments/1xhf6qp/archivetod...
The moderator conflates questions about evidence and requests for more details as "making demands" https://www.reddit.com/r/Seattle/comments/1xhf6qp/archivetod...
Its unusual and arguably suspicious because this attitude is antithetical to the stated point of the thread: To make a PSA to the community. They've also limited the comment section to only flaired users, which seems quite unusual given that this thread is ground-zero for a newsworthy claim.
Eh, still think simplest explanation is most likely here, which is that there's no secret motive, but the mods and some users over there are just dumb. I don't mean because they're nontechnical or don't have randomly specific web knowledge (one of them actually does), it's about how they responded to people.