Lupin, in Arsène's shadow

[Fyraltari]

I've got one important question though. Did, at any point, Benedict Cumberbatch appear in a cameo as a British private detective whose name very much is not Sherlock Holmes (but whose name and actions are very similar)?

Nope. No Herlock Sholmès. No Ganimard, Folenfant, Béchoux or Beautrealet for that matter.