They have had 8 person juries before, as recently as last season in Blood vs Water 2.
Natalie won with 5 votes, Jaclyn had 2 votes and Missy had 1 vote.
When there are 3 finalists it doesn’t matter how many jury members there are. A tie is always possible. And to be pedantic, When there are 2 finalists, you have to have an odd number of jury members to assure there isn’t a tie.
But in 29 seasons there hasn’t been a tie when there are 3 finalists. (14 times)
That’s an interesting point–in both cases from this season where idols were played, he stacked all the votes for the person who used the idol first. If there hadn’t been an idol, that person would have been voted of and he never would have shown who else got votes, which has turned out to be pretty important information for people to have…
When an idol is played, he almost certainly says “I’ll go re-tally the votes” and then goes back over to re-order the votes again for maximum drama. Easily edited out, of course.
That would be lame and a half. Any confirmation of that from people who’ve watched all the podcasts & twitter & such?
I can’t say for sure, but I believe they want Jeff to be shocked/surprised as well, so they just show it as it plays out. I have not noticed that he reveals votes that way, though. Maybe he has them organized and does a simple reshuffle in the box.
After previous seasons, players have said that sometimes Jeff would be “tallying the votes” for hours. Also, Jeff said about ten seasons ago (so he may well have changed his tactics since then) that he didn’t watch most of the footage on a day-to-day basis, so that he could be more surprised and react like a viewer rather than seeming to be the guy who knew everything: he’s the first member of the audience, not the dungeon master. He only wanted to know about things that might affect the production, like if somebody was injured or sick or about to pound somebody. He didn’t even necessarily know if people had found idols (or, he didn’t know right away).
This came up fairly recently in one of Dalton Ross’ weekly interviews with Probst: ‘Survivor’ host Jeff Probst reveals how he orders the votes at Tribal Council
Note: not sure why the date displayed on the linked page is from 2015… this Q&A is for Episode 10 of Survivor: San Juan del Sur, which aired on November 26, 2014.
I’ll quote Jeff for those who want the main part.
In a way, I suppose they always have to re-order the votes (whether off-camera or subtly depending on Idols being played) because they usually try to have it end with “Xth person voted out of Survivor (turns around card) XYZ!” Has there been times when Jeff has flipped around the card to show that someone else has been voted out? (Example: 4 votes for X, 2 votes for Y, X plays an Idol, if the votes were read YYXXXX then it would be weird).
On the other hand, Jeff re-arranging the votes after the time for Idol-playing has based basically gives away that there’s an Idol in the game. Late-game this usually doesn’t matter, people know it’s out there, but early on people aren’t sure.
Great, so people who think of themselves as Survivor elites will now be watching to see if somebody gets the first three or four cards in a row (rather than staggered, like he usually does) as an indicator that that person has an idol…
Maybe they have little indicators that show the order he should read them in. If no idol gets played, use the yellow dots, if one gets played for player X use the red dots, if played for player Y user the blue dots.
I believe the final-three format is a backstop against the “goat strategy,” i.e., a strong, charismatic player taking a much weaker player to the final two.
Of course, a three-finalist FTC doesn’t preclude a player taking two goats to the end, but that’s quite a bit more difficult to implement.
Unfortunately, all too easy in this “Season of the Goats.” 
Not this season–at 6, they had two players (Tyler and Mike) and four goats (Rodney, Dan, Celia and Carolyn). All Mike has to do to win this is not suck for the next few challenges. Probably wouldn’t hurt if he put a little bit of time looking for an idol, either.
How? He said he reads them in a different order if the idol is not played. How would they know?
If they had several votes where the person with the idol only got one or two votes, he’d probably just read them in the order they’re stacked, so, say, Carolyn could have been read first at three or four TC’s in a row (if she had gotten votes). Same with Mike, really, and he’s gotten more votes. Probably not a big deal, but some of the people who style themselves experts within the game get a bit obsessed.
At 6, it was Mike, Dan, Sierra, Carolyn, Rodney and Will. Tyler was gone at number 7. I’m not sure I’d call Carolyn a goat either, and she’s won 2 immunity challenges, so Mike isn’t anywhere near safe. Plus I’d be shocked if there are any more HIIs out there - usually once they’re down to 5 players left, HIIs are no longer usable.
I think final 5 is the last time you can play an idol. It can get you into the final 4, but no further.
Regarding the vote reveal after anyone hands Jeff an HII, it would make more sense to cut right after Jeff says his line, “This is a hidden immunity idol. Any votes cast for XXXXX will not count.”
Jeff can then take the voting urn out back to where the votes are cast and allow enough time to rearrange the votes (whether or not they have to be rearranged). When he returns, he just continues with “I’ll read the votes”. No risk of messing up the vote ordering or telegraphing the outcome to the contestants/audience, with the minimal cost of an extra cut in the edit. This also mitigates the need for Jeff to know who has the HII, which is a potential source of unfairness in the game.