It was a dumb ass operator not monitoring the way he was supposed to.
I am sure we will get a lot of players in the blame game before it is all over.
Shouldn't matter even if the operator was chugging back a beer and taking a leak in the ocean when this happened - these gawd-damned systems need to be idiot-proof.
That means multiple redundant back-up safety systems.
If, with all our technology, we can't do that, then we shouldn't be drilling off-shore.