Maybe she almost did, I would think losing the trail would be typical of the later stages of hypothermia.
The story said S&R found her belongings before they found her, and also that they went into recovery mode. Sounds like she dropped or ditched what she needed to survive. It's not uncommon for people in the late stages of hypothermia to ditch their stuff, including taking clothes off. In the early stages the body cuts off the flow of blood to the extremities to protect the core, and in the late stages the body loses its ability to regulate, and the blood is released, making people feel flushed. Plus, judgment goes out the window.
It could have been any number of things that sent her down the path to hypothermia, usually it's a combination. Get off the trail, get disoriented and panic, and injure yourself. Panic is a very common reaction to getting lost. Or something as simple as losing glasses or contacts and not being able to see the trail, taking a wrong turn, twisting her ankle, whatever.
And like I said, I've seen a lot of people in the backcountry who weren't carrying the stuff they'd need in a situation like that, it's not uncommon at all.
