When Sir Arnold Raeburn tells the detectives he saw Dr Ella Ransome arguing with someone, Hathaway asks, "Who?" Raeburn says, "The bassoonist." Lewis says, "The name." And Raeburn says, "Kate Cameron." But there were two bassoonists in the orchestra. And so one would expect Raeburn to say, "One of the bassoonists," or "A bassoonist." And when he does say, "The bassoonist," one would expect Lewis to ask, "Which bassoonist?"