I think a more reasonable way to look at this situation is you have a control freak(pretty sure a condition of Shanny to Washington was complete control) in a profession where winning is absolute. The race of the quarterback doesn't matter, if anyone who is a significant part of the team said he can play in that situation Shanny would of played him against better judgement.
It's shortsighted and dumb of the coach to do but it's nothing to do with race and it's lazy as fukk to create this narrative. The average person is gonna read the shock value of someshyt like this and give it validity furthering the profile of some of these hacks.