That said, you're right it's true for AU too. Nick's vocabulary and tiny details would have to be MASSIVELY well researched for him to be convincing as a doctor. LOL... But yes, it's very true. Characters even in OF need to be "in character" to be convincing. And it sooo happens even to the best of them. I've seen some REALLY good books where the author had a character step out of character and I thought it was going to lead to a major plot twist and either they missed the excellent opportunity to throw in the unexpected OR they completely missed the detail. It makes a really good book/fiction go down hill south (for me). Movies, too!