Going back to the original topic, I'm pretty sure that he was just caught up in the moment, fantasizing about everything Sherlock Holmes. Even if the Reichenbach Falls are in Switzerland, like everyone pretty much already pointed out, it's all Europe. It's just like how everyone knows everyone else in America according to anime, European locations are still European locations. Whether it's the U.K., France, Switzerland, Germany, or anywhere else, they tend to get packed together.
That's a pretty big mistake for someone who is supposed to be writing about a character obsessed with Holmes, ESPECIALLY when he actually traveled to Europe to do research. So my only conclusion is that it wasn't a mistake (see first sentence).
