I've always felt that the movie, unlike the book, failed to show how obvious it was that Gallo, who was credited with the co-discovery of HIV, obviously got his samples from the French laboratory (they were genetically identical).
Having worked for over 30 years in an R&D organization of a Fortune 500 company, I can tell you that this type of behavior is not uncommon. When a researcher discovers something that promises to be a big revenue generator, people come out of the woodwork seeking to be associated with it. I learned early on to be scrupulous about lab notebooks and filing patent memoranda promptly. As they say, "success has many fathers but failure is an orphan."