Jon`C covered everything I would have. This was not going to be a winning case at trial and probably never should have been taken to a grand jury, but the prosecutor was under pressure to do something and made the political calculation that he'd catch less flak if he made the grand jury deliver the bad news. He was almost certainly correct.
Like Jon said, this case was a bad example of a problem that's nevertheless very
real. Unfortunately, the Average White Person is treating the fact that this case is a bad example as evidence that the problem isn't
real.
I think what you're missing is that this was a grand jury, not a trial (or petit) jury. Without going into too much unnecessary detail, in American criminal justice, a prosecutor is typically required to bring his case to the grand jury to obtain a "true bill of indictment," which is basically a certification that there is enough evidence to justify proceeding to a trial. So the grand jury wasn't deciding on punishment, it was deciding whether there would be a trial.
What's unusual about the situation is that the prosecutor didn't recommend that the grand jury issue an indictment. How much this matters is up for debate. Usually, you can infer from the fact that a prosecutor has brought a case to a grand jury that he thinks the defendant should be indicted, because if he doesn't, what's he doing in front of a grand jury? Here, though, because the prosecutor was under obvious political pressure and seems to have brought the case to the grand jury purely out of a sense of obligation rather than out of any real hope of (or interest in) obtaining a conviction, I'd say it's fair to suspect he may have been soft-pedaling the case by withholding his recommendation.
If you think the waiters are rude, you should see the manager.