For your daily media competence training:

The hint that the above AFP #BREAKING tweet was nonsense is the use of the word may. Like in "#BREAKING Sky may have fallen". There is also the rhetoric redundancy in "have starved to death".
But notice the 217 retweets which likely will have caused many secondary retweets and many, many more viewer impressions.
Three hours later …

The #CORRECTION is of course not #BREAKING. People searching Twitter with the hash-tag #BREAKING to take a quick look at recent news will of course never see any relevant #CORRECTION. You can simply make up whatever nonsense you like to distribute into a #BREAKING news stream, preferable with one of the agencies or other prominent accounts. You will then get a huge distribution. Later you issue a #CORRECTION which exculpates you from the error but will not be read by anyone.
But in this case of the "UN rights chief" claiming something may have happened it was surely really just a clerical error or a misunderstanding. Right?