It's the overall culture which allows for white police officers to almost universally get away with, or get handed light sentences, for murdering unarmed black and brown men. The fac that some (and this isn't a strawman, I've been hearing this all day in the news) are lauding this verdict as a step-forward because the officer at least got convicted of something, shows the sad state of this kind of an affair.
There's a tape of the shooting widely available on line. After the initial incident, the motherfucker fled to Arizona. For the first several months afterwards, he used the excuse of "I thought I saw him reaching for something", despite the fact that the man had his hands cuffed behind his back.
I don't know why the jury gave the verdict they did, but I don't think we're being overly cynical to see it as white cop= not accountable.