Not sure exactly what the judge meant there -- but I hope those people went to jail and were not just fined.
How does BP get away with it? The same way the Godfather got away with it: bad things happen to folks who blow the whistle. BP has a habit of hunting down and destroying the careers of those who warn of pipeline problems.
In one case, BP's CEO of Alaskan operations hired a former CIA expert to break into the home of a whistleblower, Chuck Hamel, who had complained of conditions at the pipe's tanker facility. BP tapped his phone calls with a US congressman and ran a surveillance and smear campaign against him. When caught, a US federal judge said BP's acts were "reminiscent of Nazi Germany."