This opinion is a civil case, but nothing about it suggests to me that the same rule wouldn't obtain in criminal cases in analogously unusual circumstances.

Dietz v. Bouldin, No. 13-35377 (Fisher with Bea and Murguia) --- The Ninth Circuit held that if a trial judge makes an "appropriate inquiry to determine that the jurors were not exposed to any outside influences that would compromise their ability to fairly reconsider the verdict," the judge may recall a jury shortly after it has been dismissed to correct an error in the verdict.

This case involved a suit for damages following a car accident.  The defendant had admitted fault, and the parties had stipulated to the amount of damages to award stemming from the accident, so the only issue at trial was the amount of damages for future treatment.  The jury had been instructed to award at least the amount of stipulated damages, but they returned a verdict of zero dollars instead.  The judge thanked the jury and told them they were free to go.  But "moments after having dismissed them," the judge recalled the jury because their verdict was contrary to the instructions.  After inquiring about any potentially improper influence that may have occurred during the momentary dismissal, the judge reconvened the jury and reminded them they had to issue a verdict for at least the stipulated amount.  The next morning they returned a verdict for more than the stipulated amount.

Most courts of appeals allow the judge here to do what he did under the circumstances and in the face of the appropriate prophylactic discussion with the jurors that happened here.  But the Ninth Circuit had never decided what should be done here, so they had to publish an opinion on this score.  The Eighth Circuit has a bright-line rule that says once the jurors leave the courtroom, the judge can never reconvene that jury.  The Ninth Circuit didn't like that rule because it was too rigid and didn't account for the possibility that the jurors could receive improper outside influence even while they're in the courtroom now that everyone has the internet in their pockets.  So the Ninth Circuit went with the flexible rule, requiring only the prophylactic discussion.  Because that discussion had occurred here, the court found no abuse of discretion and upheld the jury's verdict in favor of the plaintiff.

The decision is here:

http://cdn.ca9.uscourts.gov/datastore/opinions/2015/07/24/13-35377.pdf