I don't think any of the Ometepe tribe have done anything wrong strategically. Most of them are probably just hoping to earn $100,000 by making it to the finale, and, even if they wanted to make a move against Rob, it wouldn't make sense to do it so early. It's better to wait until the Zapatera tribe is either gone completely or down to 2 or fewer members (especially given the Redemption Island twist, which can screw up the numbers analysis).