How Does Kevin Systrom Disagree With Mike Krieger Without a Fight?

Mike Krieger said on Partners that he and Kevin Systrom raised their voices once, for about 30 seconds. Early on, Krieger wanted a day at home so he could code all night. Systrom wanted a shared office. Krieger tried it, and they moved faster in the same room. Systrom will not agree just to be nice, and he will not make you feel bad for disagreeing. He says what he wants and asks why you see it differently. He cares about character and follow-through, not a wrong tool or a bug. Cofounder was the real title. CEO and CTO were labels for events, and someone still has to break a tie.