BP's (BP 0.71%) legal troubles are far from over. Phase 2 of its trial resulting from the 2010 Macondo well spill starts Monday, dealing with how many barrels were released during the 86-day spill. Billions of dollars are at stake as the company wants to come out with the fewest barrels it can, while the government wants to prove that there were more. Senior analyst Jim Mueller tells how investors should be thinking about the whole situation as it plays out in the courts.