That's not what a plothole is, it seems like you're just trying to create excuses to justify it. A plothole isn't something that doesn't make sense, it's a major flaw in the story where it ruins the movie. This is a common problem.
Your right in that plothole does seem to not be the right word. I guess a flaw would be accurate but I wouldn't say it's a major one. It doesn't really impact the story that much. I don't think were are suppose to think he carries these drugs around because he is a sexual creep either. I think a shortcut might be a better label. It's not their to say anything about the character but simply serve as a means of getting the Dana character to go to sleep.
Jason