Because the law differentiates, not me. When the GJ does not return a True Bill it means that a jury of our peers believes there is insufficient evidence to charge someone with a crime.

That is a wholly different definition than jury nullification, where one or more members of the jury return a "not guilty" verdict because they reject the law or its application irrespective of the defendant's guilt.

The standard of proof differs. A GJ is not required to find a defendant guilty; instead, they must determine whether there is sufficient evidence to suggest the possibility of a crime. The subsequent proceedings will then determine the outcome.