What's most interesting, at least from a journalistic perspective, is that he never actually gives the answer to the question. Seems more than anything he has a problem with Buzzfeed. He should probably focus more on how social media allows mob mentality to rule the day.Interesting article regarding this situation and another perspective.
Why Did BuzzFeed & Co. Target Justine Sacco for Online Assassination
"Going to Africa, hope I don't get Aids" would be considered a joke, not a creative joke, or a good one, but a joke nonetheless. Inserting race into it takes the humour out of it entirely and makes it come across as mean spirited. The real irony is not that she's a PR exec, but a South African native.
She's put out a written statement apologizing for the Tweet. She'll be alright, though, her dad is a South African mining magnate worth $1.5 billion.