We can already assume the judge is going to find BP grossly negligent. People are going to suck out as much money as they can out of them. Why wouldn't they. This is once in a lifetime opportunity for a no name judge. He is going to prolong this trial as long as possible. No one wanted this go on as long as the Exxon Valdez trial, except the judge, lawyers BP hired for their defense and the people who are sueing. The are going to suck out as much money as they can, why wouldn't they.
Federal Judge Barbier seems like he wants to be fair. But a cynic could just as easily respond to you by saying the 5th Circuit (which is where a gross negligence finding would be appealed to) is overly pro-business and comprised of former oil/energy attorneys who will do anything in favor of BP.
But even granting this type of cynical view, the probability, based on what I've read from legal eagles and those types, is that any gross negligence finding will likely end up in the Supreme Court.
So start speculating what those 9 Justices would do - that's more relevant in the long run.
But I agree - when Judge Barbier finds gross negligence, there will be a big hit to the share price!!