Mayday, pilot incapacitation
Sorry I might have missed a bit of info here but according to my knowledge loosing a member of the on-duty flightcrew is an emergency regarless of how many other pilots may be on board... unless you call yourself M. O'Leary...
If not considered an emergency why diverting then? they could have continued to destination with the spare Cpt...
Let's just pay respect to the fallen one and hope this doesn't happen again