Coast Guard Admiral Thad Allen gave BP another 24 hours, starting Sunday evening, to keep testing its cap on the Deepwater Horizon. Admiral Allen is worried about signs that the seabed around the well is leaking -- "undetermined anomalies," as he wrote BP (letter linked here). At the far end of the spectrum of fears, officials worry that capping the well may create enough pressure to cause the sea floor around it to break up.
Which could seriously be bad. If the Coast Guard doesn't like what it sees, it will ask BP to open up the valves on the cap and let the oil flow again. "At any moment, we have the ability to return to the safe containment of the oil on the surface until the time the relief well is completed and the well is permanently killed," Allen said.
How big a deal is this? The folks at the Oil Drum spent the weekend talking newbies off the ledge. @Rovman advised: not making too much of any given video image.
All I'm trying to say is that throughout this event I've said to myself 'Oh, some disturbed silt again' a hundred times but never once have I said to myself 'Uh-oh that looks nasty!' Remember also that if there is a leak worth worrying about down there, there will be an ROV stationed next to it 24/7 with a camera trained on it. That's what you should be looking out for.