None of those directors was in the least bit uncomfortable. That's a tactic I've seen white people use against non-whites when matters of race come up.
Absolute silence. Let the non-white person rattle off a list of justified critiques and facts while remaining stone-faced while in the back of their minds, "Whatever n*gger. It doesn't matter what you say, you're still a n*gger."
It's called "White Silence In Racial Discussions". Dr. Joy DeGruy brings this up a lot in her talks.
===== From the so-called White Privilege Conference =====
This paper analyzes a common dynamic in interracial discussions on race: white silence. Using whiteness theory as the frame, I explicate the common white rationales for silence in discussions of race and challenge each of these rationales from an anti-racist framework. These rationales include: “It’s just my personality—I rarely talk in groups”; “Everyone has already said what I was thinking”; “I don’t know much about race, so I will just listen”; “I don’t feel safe / don’t want to be attacked, so I am staying quiet”; “I am trying to be careful not to dominate the discussion”; “I don’t want to be misunderstood / say the wrong thing / offend anybody”; and “I already know all this.” I argue that regardless of the rationale for white silence in discussions of race, if it is not strategically enacted from an anti-racist framework, it functions to maintain white power and privilege and must be challenged. - Robin DiAngelo
=====