No, but for a conviction, they need every single juror, so even one is an issue.
Only in support of conviction, not acquittal.
The bottom line is that the rules for juries are downright weird, and appeals judges hate to overturn them.
In two noteworthy cases, it was decided that a juror could use a coin flip to determine guilt or innocence; but that a juror could not consult The Bible in determining it.
One juror statement that did not overturn was after the trial of a murderer, a juror said “I was willing to give him (the defendant) the benefit of the doubt until he flipped us off. That convinced me he was guilty (of murder).”