The poster of https://www.lexaloffle.com/bbs/?tid=141370 seems to have discovered that posting a short reply to their own thread un-hides their original post after it was flagged for spam review. Not 100% sure this is a bug, but it seems like one.

(when I saw that thread, the reply was flagged as spam but not the OP, then I flagged it)

Oh interesting - I flagged it (unless I've horribly misremembered things), it got hidden, then reappeared after the reply. But now it does show as hidden again. So maybe there's some thresholding system here. Since additional flags will still result in the thread getting hidden, this seems much less bad.

Huh, when I visited the page later, it said [under spam review], but when I mark it as spam and go back to the page, I can see the contents. Odd.

Weird! Yeah, I thought I understood what was going on, but now it's all un-hidden again. No idea.