Did BP Start Losing Containment of the Oil Well in February?

From Washington's Blog

The Deepwater Horizon blew up on April 20th, and sank a couple of days later. BP has been criticized for failing to report on the seriousness of the blow out for several weeks.

However, as a whistleblower previously told 60 Minutes, there was an accident at the rig a month or more prior to the April 20th explosion...

But the trouble was just beginning: when drilling resumed, Williams says there was an accident on the rig that has not been reported before. He says, four weeks before the explosion, the rig's most vital piece of safety equipment was damaged....