I used to live in Las Vegas and it is very common for people who love the heat to hike this way, especially if it's not backpacking but a couple of miles in a loop on a nature trail. They love to get tan. I've never seen a man in a Speedo but it's common to see someone in boxers or cutoffs, with or without a shirt.
The sheriff's statements are off-putting to me because they say there's no evidence of abduction; but there's also no evidence that I see of any other kind of crime. It seems like they're closing the case and dismissing it too early. If you look at the example of the other woman who had to evade a knife-wielding attacker for four days, the cases are actually quite similar: both areas are remote campgrounds, both couples, both cases of women who were with men so seemed to be safe, both did something ordinary like walk a dog or take their beer back to the RV while their husband was distracted with another task.
Both women were petite or on the small side, neither was particularly young. The two sites are actually within an easy day's drive. Police have not caught the potential abductor in the first case. I don't find it hard to believe that a small woman could be intentionally bumped by a car hard enough to knock her down, put her in the car, and drive off - that would take 3 minutes max. No evidence. That's exactly what happened to the woman in Montana who was out for her ordinary jog when abducted by two oil workers (IIRC).
There is another case current that is disturbingly similar. Further north, at Discovery Bay, a rather rural hamlet, a woman went out to water plants - husband inside the home - and disappeared. Her husband flagged down cops. An extensive search found her body in the water nearby. Petite older woman.
To me, I wonder if there is another Golden State killer around, a thrill killer who gets off on abducting and killing women whose husbands are right nearby.