I'm as perfectly baffled as many. I did a small round of chats, but everyone I spoke to is just scratching their heads just like I do. So I think I'll just echo your observation for now: I don't know of any prior example that could possibly have helped in anticipating this disaster. This is a super blow out of mud - has that been observed in the oil industry before?

While I was reading up on it, I found this beauty of insult after injury: "At least the mud is not toxic".

As for a calm peaceful Earth, that's an illusion humanity has selected because we've been relatively abstained from sudden, catastrophical events. And in that tangent, I am the one predicting gloom this time: as long as the human population grows, these kind of disasters will get a whole lot worse in scale, number and severity. And if Yellowstone would actually go, we're really in for a world of hurt.

(BTW, small correction, the Siberian traps are dated some 249-250 million years ago. The Wikipedia entry is deceptive at this point by stating it was "the biggest in 500 million years". Check out the website at the University of Bristol, here, for an easy introduction on the topic.)