Some members of the Transocean crew invoked the Fifth Amendment, probably on order from management because of the liability ramifications.
BP, Transocean and Haliburton have been ordered by the Justice Department to preserve their records. Attorney General Holder announced both a criminal and civil investigation.

Investigators will look for violations of the Clean Water Act, the Endangered Species Act, the Migratory Bird Species Treaty Act and the Oil Pollution Act of 1990, among others. Responsibility for the killing of 11 workers and injury to 17 others will be determined.

This will be a complex and extended series of actions.

Oil and Gas International Report, June 2, 2010.