I just reviewed an answer on Travel. It was clearly spam and I flagged it as such. The moment I did, the review screen reloaded with the answer in red (because it had been deleted) and some stuff about being deleted by Community and so on. Above the now-deleted body was the warning:
Our system has identified this post as possible spam; please review carefully
Duh! I just flagged it as spam dudes, I am on board with this.
All that was left for me to do was click I'm Done and wonder why I was given this warning after I had clearly reviewed carefully already.