I noticed a bug recently, and I came across it today again which reminded me to report.
Sometimes a very low-quality post is made, usually by a transient new user, which is automatically flagged by the system; as well as several users who flag it as low quality or "not an answer". It used to be the case that these posts would accumulate flags until the moderators deleted them; then trusted users were allowed to delete those posts themselves. Both these actions automatically clear the flags.
However with the introduction of the new review system, ordinary users (read: not trusted or moderators) can vote to delete answers and if there are enough recommendations to delete, the post actually gets deleted. Although it doesn't say that it got deleted after being reviewed by six users or so.
I noticed that sometimes(?) flags being made on the posts are not cleared up. This causes the post to appear in the flagging queue despite being deleted, and what's worse is that I can't really flag or vote to delete... because it's already deleted!
Example: A proof of the fundamental theorem of symmetric polynomials and here is the review log (obviously only 10k+ can see this, and only diamond mods should be able to see the flags; I'm not sure who can see the review log).
While I'm at it, perhaps change the "Deleted" text to point to the review log in the post itself? It would be as reasonable as writing the names of those who voted to delete in the ordinary case.