No adjudication took place because there was just a hearing, not a trial finding facts.
True; but does that mean that he was never placed in that jeopardy? After all, the Grand Jury's place is to (a) see if the charge fits/has-merit [indictment], or (b) bring charges themselves [presentment].
Murder is still a capital offense, therefore the Fifth Amendment's restrictions on prosecution are in place; moreover, as the charge was dismissed at the initial stages, to draw up new charges based on the same actions is precisely the meaning of subject[ing one] for the same offence to be twice put in jeopardy
, and lastly, this re-drawing up of charges/grand-jury-shopping is exactly bypassing due process of law
(that is to say, it's merely giving the appearance of complying w/ the strictures, while in actuality ignoring them).