Having not seen the case presented by the accused defendant, I can't say whether the Supreme Court could have reached any other decision without evaluating arguments that were not put before it. Unfortunately, if someone who appears before the Supreme Court fails to make what would have been a winning argument, their loss at the court ends up being effectively binding upon people who were not parties to the case, and who could have presented better arguments.
For the Double Jeopardy rule to have any effective meaning, a retrial after a mistrial should only be allowed when (1) it's likely that the first jury would not have acquitted, even if it had been allowed to do so, or (2) the mistrial was caused by the defense's actions, or (3) the mistrial resulted from unforeseeable circumstances which would not have been prejudiced against the defendant. If the failure of a jury to render an official verdict would be sufficient to declare a mistrial, a hostile judge could declare "mistrial" on any case he thought he would lose.
I generally agree with your reasoned posts on this thread, but that word "likely" is problematic.
FRegards,
LH