I believe in the PIC's authority, but unless there was a safety risk resulting from this incident, is it really appropriate to divert a flight? Just having an argument with another crew member or some other type of disagreement? Now before we all jump on the 'we don't know the circumstances here so let's withold judgement'; let's discuss this in the broad sense of ANY flight. What type of situation would be a serious enough of a safety risk to rate diverting the flight. I'm also making an assumption here that diverting a flight is a pretty big deal for reasons from scheduling, cost, and passenger inconveinence.

USMCFLYR