So, the issue is "Where are Kelly/Christy? Where are Andrew/Dan?" ..........
I found Andrew & Dan in the "Land, Air and Sea" Preview.
I was just watching CBS shows from Fri night and decided to watch one of the commercials for anything new. Caught sight of A/D. Rewound and using Pause caught A/D just after the "By Sea" is shown and just before Sarah yelling fast, fast,..... The frames show A/D on a boat probably still in the river.
Since N/S is 1st, D/T 2nd and K/T 3rd then A/D is 4th if they bypass T/S; or 5th if T/S stays ahead of them. As to K/C at this point we only know they aren't 1, 2 or 3.
At CBS.COM the thumbnail for the 1:00 Preview under the Episode 5 clips has a frame with A/D. Click to watch and pause at 25 sec and A/D on a boat will be found.
The new preview today has the V/O about the secrets of Cambodia. At the V/O (right after showing T/S boat breaking down there's a shot of what looks like A/D in the water loading a basket into their boat. Right after that is a shot of Aja walking in chest deep water. Aja is wearing a pink top near the small pens. She was not carrying or pulling anything.
It appears K/C are the only team that did the teeth, etc.