One tweet didn't wipe $8bn off its value, the results did. If the results were released next day, it still would have lost value ffs. I feel angry reading through this and realizing it was a waste of time fluff.
Say what you will, its evident that HN crowd loves sensationalism more than content, as seen again and again.
I'll ask the same thing I asked someone else: You're saying if Twitter released their earnings as planned after closing that today after opening they would have still lost $8Bn? That is the relevant fact reported by BBC, and I highly doubt Twitter would have dropped by that much if investors slept on the news.
I don't know how much truth is in those two points, particularly the latter, but that's what the article is about.