Any time Data plays the part of Sherlock Holmes he's shown as wearing a deerstalker cap and smoking a goose necked pipe. Holmes only wore a soft cloth cap (drawn as a deerstalker though never said to be one by Holmes creator Arthur Conan Doyle) when in the country, not in the city. Also Holmes never once smoked a goose necked pipe. That was an alteration made by an actor who found that it was the only pipe he could hold between his teeth and still be able to say his lines clearly. Finally, Sherlock Holmes never once spoke the words "It's elementary, my dear Watson." That was something else added in a script but never once written by Doyle. An android would get these details right.