There is a plot inconsistency here in Conrad's otherwise meticulously plotted
novel. Not just Decoud, but Charles Gould agrees that maintaining the flow of
silver to Holroyd is essential for the Separatist plan. In fact, that assumption
is the whole motive for the adventure in the Gulf that follows. And yet, when
the silver fails to reach Holroyd, Gould continues the plan of Separation
regardless, and succeeds. One can defend the inconsistency by saying that the
characters simply reconsidered the situation and changed their minds, which would
be consistent with the theme, yet still vexing for the reader.