AP quoted a New Jersey attorney: "It's a fundamental principal of New Jersey law that anything that is 'clearly exculpatory' should have been included in the presentation to the grand jury. But it's a little fuzzy over what constitutes 'clearly exculpatory.'"
The AP story also addresses the fate of the other Rutgers student involved in the Clementi matter:
[Molly] Wei later agreed to testify against Ravi in exchange for being spared a trial and having her charges eventually dropped if she complies with certain conditions.
Recall that the basic charge was invasion of privacy of Tyler Clementi.