The civil suit against BP brought by the US government on Wednesday had been inevitable since we first found out that thousands of barrels of oil were spilling into the Gulf of Mexico. The timing of Wednesday’s announcement, mandated by the judge at the New Orleans court where the trial will be held, was the only surprise. It perhaps did not send the best message about the business-friendly nature of the administration, on a day when President Obama was courting many of America’s top CEOs.

The share price reaction was modest, reflecting the fact that while the headlines are terrible for sentiment, investors always knew this day would come. The news looks bad for BP, but shareholders can still hope for better, as the Lex column points out.

Nevertheless, the Department of Justice’s action is a salutary reminder that, eight months after the fatal accident on the Deepwater Horizon, and three months after the ill-fated Macondo well was sealed for good, BP is still not even close to finding out exactly how much the disaster will cost.