In one of the lectures of your professor, you heard him say somewhat different from what you learned or read. What do you do? I mentioned before you may want to discuss the matter with him privately and in a respectful manner. But what if after the discussion he maintains his position, what then should your answer be if that would be asked in the exam? Then you have to give the answer as taught by your professor. Remember he is the one who will check your booklet. However, be sure you know what the correct answer is when asked in the bar exam.