There are some unanswered questions here for me. But before I point them out, understand that I lived in Oregon for over 40 years, spent many, many days backpacking and hiking in the forest, some on remote trails, some solo. I've also been throughout the western US doing the same. And I've been to Yellowstone, more than once. I have seen bears on trails, and a few who appeared "lost", even one walking on a road. I never had any sort of confrontation, but did surprise one once, about 40' from me on a trail (it ran off scared, which is their normal behavior). I also have a cousin who was a USFS ranger for 35 years.
Here's what I don't understand:
• Did the NPS know there was grizzly bear activity in the area where the hiker was killed? While there can be bears anywhere, history has shown that rangers get a lot of feedback on the general whereabouts of bears, especially in National Parks. Furthermore, was this bear and her cubs on a popular trail? Or was the trail remote, and no one had visited in a while and the ranger information on it out of date? If the NPS knew the bears were in the vicinity and this was a heavy bear area, did the put up signs indicating it? Have they been telling hikers about the area?
• We still don't know what the hiker did. Was he blindly walking along, came around a corner, and found himself between the cubs and the mom, who promptly freaked out and quickly attacked him? If so, that's just sheer bad luck and I feel for the guy and his family.
• Did the man come prepared? Did he have bear (pepper) spray? It sounds like people didn't even know he was missing. This is shameful since he was a park employee of some sort. Pepper spray won't ward off all bears, and misusing it can be worse than not having any. But we don't know these answers. It's also likely we'll never know what he did when he encountered the bears. What action he took.
• Did the NPS consider closing the trail, and adjacent trails for the rest of the season (only about 2 months to go), before just catching and killing the bear and leaving the cubs motherless? Or was it part of such a popular network, or very close to civilization, that this was impossible? I have been to areas in the Cascades and Sierra Nevada mountains where there have been bear encounters, and the USFS closed trails, and issued warning signs at all nearby trailheads, indicating heavy bear activity. In every instance we all knew what that meant: There's always another hike elsewhere, or another day to go.
• Did the NPS consider capturing and transferring the mother and cubs to a remote area in the park, or adjacent USFS land outside the park? While not common, this has happened before. If dismissed, I'd be curious to know the reasons why?