In that scene he remains perfectly calm in the face of Woltz's tirade. That reflects his complete confidence in Vito's ability to get what he wants for Johnny and his advice to Tom to never get angry and never let anyone know what you're thinking. Perfectly played. Of course the, "Mr. Corleone insists on hearing bad news immediately" is classic.

"Generosity. That was my first mistake."
"Experience must be our only guide; reason may mislead us."
"Instagram is Twitter for people who can't read."