FIFY. To answer your question I say the same thing I did during the Trayvon Martin fiasco: if you confuse MSNBC's spin with actual evidence and cannot be bothered to educate yourself on the actual legal standards, of course you'll be surprised that this was the outcome.
The saddest part is that we'd think logic dictates when case after case is decided opposite of the media's suggested resolution, people would begin to realize the media is wrong at the least and complicit at worst. Instead, they come to the conclusion that it's an epidemic of racial and/or LE hateful violence. Because drama.