What are some of your nittiest of nitpicks?

I think I may have found mine. In the new trialer for the Will Ferrell/John C. Reilly movie Holmes and Watson, there's a part where they accidentally break the glass on a container housing killer bees. Killer bees, a.k.a. Africanized honey bees, didn't exist until the 1950s, while the movie appears to take place in the 19th century. Very nitty, but I just had to pick it.