https://www.theguardian.com/world/2019/mar/21/facebook-could-have-moved-faster-on-christchurch-video-if-it-were-suicide

Site says recently live streams are prioritised for review only when flagged for suicide

Facebook has released more details of its response to the Christchurch terrorist attack, saying it did not deal with the attacker’s live stream as quickly as it could have because it was not reported as a video of suicide.