Respectfully disagree. The trail that intersects the "main trail" at about 1/4 of a mile in is not obscure. It is a commonly used trail, quite a bit wider than a deer trail, and it heads down toward the Research Center. Also, the trial that leads to the dry wash from that point looks to be as wide as the actual trail. You can see the dogs start down it in the SAR video (IMO) and they are called back due to the tracking method the handlers are using.
He apparently said the "dry creek bed" thing to a reporter who arrived on site and it was part of a now-unavailable TV broadcast (I've asked, I've been told the station no longer has the footage; the reporter does not want to be "involved in the case" and can't say whether they remember what he said). However, I do remember it (and heard it more than once, as it was local news here, as well as in Vegas).
They were on the main trail - but not the entire time. The "main trail" does not go to the top of any hill or pile of rocks. There are no trails across the rocks. There are about 5 short spur trails leading into the rocks, toward the top of them. But we don't know which one they were on.
However, it's clear that LE used the intersection between the main trail and the trail that leads down to the wash as a central point in the search, as it shows up several times in the video. What we don't know is whether Barbara was actually right there. But it doesn't support RT's story that he went to the wash to take pictures. At the time it made a lot of sense to me, because dry washes do photograph beautifully and that's why there's a trail to it. That trail goes beyond the dry wash and to a rock formation that looks a lot like the rock formation that's easy enough to hike to the top (the granite formations are not easy to scramble up, that I know from personal experience).
So, if they climbed a hill, they were no longer on the main trail. A lot of people decide to go down the back of the rocks and there's a trail that circles around and goes back down to the wash.
We don't know where they were, but the SAR dogs appear to start their search at the junction between 2 trails (and I believe it's the junction 1/4 of a mile from the road, or else it would have been obvious to LE that RT was lying).