Not true. You either don't know what a grand jury is or you don't know what a bench trial is.
In a grand jury, the accused rarely gets to present a defense. Hardy was allowed to present his defense at the bench trial. Also, a grand jury has a much lower burden of proof. In fact, a grand jury doesn't have any burden of proof at all. They just need to decide if there is enough evidence to proceed with a prosecution. The bench trial has a high burden of proof: beyond a reasonable doubt.
But yeah, besides all that they're practically the same.