A voided conviction is not the same as an acquittal.
Retrial is not possible if the verdict is overturned on the grounds of evidentiary insufficiency, rather than on the grounds of procedural faults. As noted above, if the trial court made a determination of evidentiary insufficiency, the determination would constitute a final acquittal; in Burks v. United States 437 U.S. 1, (1978), the Court held that "it should make no difference that the reviewing court, rather than the trial court, determined the evidence to be insufficient."
My understanding is that the court made a determination on appeal (review?) that the evidence was not handled properly, threw out that evidence, and then made a determination that the evidence remaining was not sufficient for the case to have even been tried. In this US, this does result in a "final acquittal" and cannot be retried, even if new evidence comes along later. If there was new evidence, the prosecution had the opportunity to file motion to introduce it during the appeal itself, just as it did during the original trial.
This is why DAs will make sure their evidence (and evidence chain) is rock solid prior to going to trial. They're better off dropping charges and waiting until they've got sufficient evidence to go to trial and get a conviction, then to go to trial with shaky evidence, get a conviction, but then have it thrown out later on appeal. Because in the former, you can try the case when/if new evidence appears (subject to statutory limitations of course), whereas in the latter, you're done. You screwed up. Once acquitted, that's the ball game with very very few exceptions. Edited, Mar 29th 2013 5:56pm by gbaji