"...apparently victim had told him he had a licensed concealed weapon before shooting and cop then asked for ID..."
I'm wondering if that was the cause right there; person in car announces to officer that 'I have a gun' or something similar (meaning 'I have a legally carried concealed weapon')*, while reaching for permit/licence, but officer hears the one word 'gun', sees the movement, draws and fires. Doesn't make the event any less tragic, doesn't mean racism wasn't a factor, but possibly worth considering.
*There are lots of tips online about dealing with a traffic stop while posessing a legal weapon:
"The following phrase is commonly recommended “Officer, I want to let you know that I have a concealed carry permit in this state and am currently have one on my person. How would you like me to proceed?” Notice we said ‘have one on my person’. This is very important, as the last thing you want is another officer coming up on the other side of your vehicle and the first thing he hears is GUN."