I don't think the grand jury is just sitting there playing on their phones waiting for the government to tell them it's okay to give their decision.
I do think the local government probably is happy that the grand jury process is taking so long, and they do probably want it to take a long time. They are still presenting evidence to be weighed, and they are presenting everything to see if charges should even be filed against the officer... but then, that's as it should be.
I do think the local government probably is happy that the grand jury process is not open to the public, so it got them out of the news every day.
Until we get the evidence presented as a matter of public record, there will be no way to discern if the grand jury made the correct decision in pressing charges or not pressing charges.