American Gangster

There are some very positive things about this movie — terrific performances by Denzel Washington and Russell Crowe; a dramatic story filled with irony and action. It did raise some questions for me, however. What is the difference between homage to past gangster films, and plagiarism? Why include the statistic that 30% of combat troops in Vietnam were using hard drugs, when we know now that isn't the case? Is it fair to suggest that cops and criminals are merely different sides of the same coin?