RDR2: Camp Conversations: Sean and Kieran re: Colm O'Driscoll

I've never heard this conversation before, but coming back into camp after whuppin' it up something mean, I walked in to find Kieran speaking with Sean about being welcomed despite his former allegiance to Colm O'Driscoll, and therein, Sean corrects him with the correct way of pronouncing 'Colm' which is 'collum' or more accurately, ''C Uh lum'' when in Ireland.
I did think it cruel of Arthur while 'greeting' Kieran to abuse him. Passive-Aggressive or what? I honestly was expecting some dialogue that supported his viewpoint after Sean intimidated him.