What "needs to be done" its for trail users to be aware of risks. When we run around on trails, we are emulating the prey of these animals. Proper awareness and preparation in case of confrontation is advised. I have never been hypothermic in an alpine environment despite 45 years of adventuring in it; the reason isn't because of taking comfort in statistics of how "rare" hypothermia is, rather in being aware of it's danger and avoiding it accordingly.
As for cougars in this area specifically: as I have stated, 15 years ago I was pursued and faced off with a large male cougar 17 miles west of the location of this fatality. I am quite certain that if I hadn't detected it's approach and taken aggressive countermeasures (facing aggressively, yelling, keeping eye contact, picking up sticks and rocks), I would have been attacked. As it was, I had to face off with the animal for 15 minutes at a distance of, at first, 10 feet, then 30 as it repositioned itself in the foliage. I can tell you there is no more feeling of helplessness and primal survival than such a confrontation. I view it as a gift of reminding me of my personal mortality and vulnerability, and I have appreciated every step I have taken since that evening.
Cougar/human interactions in this area are common and on the increase, as a trail use skyrockets . Ultra runner Yitka Winn has twice attempted the "Issy 100" , a rugged self-supported traverse of the local peaks, and both times ended with a mountain lion confrontation. The first was at mile 99, the second was around halfway. She has no plans to attempt again, AFAIK.
I won't go into the issue of bear attacks, but here is a tragedy from an actual mountain race last year:
There are many hazards in running in remote areas, and I have encountered many of them in tens of thousands of trail miles over nearly five decades. If you are not prepared, physically and psychologically, to deal with worst-case scenarios, you are much more likely to find yourself in them. Just like the fatalities we see on Everest, when underprepared people take on difficult environments, expect stories like this one to result on a fairly regular basis.