Did Robarts die at the end?
I think the fact, that the nurse surrender at the end of the movie and even gave him his "brandy bottle" showed that this court trial and all the brandy and cigarettes he smoke during the trial was too much for him and he died most likely. Perhaps even the scene where Helm killed Vole was just his wishful thinking while dying.
The scene is not only supposed to appear funny. It really is. But it doesnt have any fitting spot within the logic of this movie.