Even in this casual exchange there are multiple levels of plot and character action.
Later we learn that Charles is prepared to blow up the San Tomé mountain
(and sacrifice the prosperity of the country) rather than suffer defeat in his
cause; thus he himself is the "untoward event" that could destroy his
work. On a second reading, then, we feel that Charles' "unmoved" silence
at Don José's misplaced compliment covers feelings of remorse and determination.