Yes it was a mistake, but I can understand why they did pick a team they did still see in the beach area.
As for Zac, I wonder if this is like Brennan from first season, or if he is just quite.
Brennan was never shown talking, Rob always talked for his team. Well find out after the season was over Brennan was a Chatty Cathy he was just long winded took for every to get to the point. Rob was sound bites, so that's what works best on the show, not long conversations.
But I just don't get why so many people seem to dislike Andy & Tommy. One private religious superiority moment (thanks for keeping that private), and good relations with each other, other teams, love the locals... Not a single harsh word from either of them. Even there comment about the Bible was pretty tame compared to what some racers have done (and in front of others no less) about other religions and cultures.