A big problem that I'm seeing, at least amongst some of my white friends, is that the eyewitness accounts by black witnesses are automatically discounted without explanation especially when their account goes against their worldview.
I'm not sure if they'd feel differently if there had been a white person nearby to back up the other eyewitnesses but it seemed like their attitude was automatically that those people must be lying without even a second thought or debate.
I saw the exact same thing during the Trayvon Martin saga. Every conversation with them started with how everything happened exactly the way George Zimmerman said without a second thought about any other possibility or how ridiculous Zimmerman's many stories were.
I swear, the cop could come out tomorrow and say that Mike Brown got in and out of his police cruiser to snatch his gun using trans-space warp teleportation and all they'd say in response would be "plz, typical black people always going around breaking the laws of physics anytime they feel like it.".