Boy.... Right When I Saw
*POSSIBLE spoilers? (not really but everyone gets so pissy about it these days)*
His blooded sock hanging on that branch, what are you THINKING!? Few rules with bear areas. Always raise your food (they do this), bury/burn leftovers you don't plan on eating and bloodied items (whether human/animal), and always wear a bell on your pack in ADDITION to talking or clapping periodically. If you smell an offensive odor or circling birds evacuate the area and use extreme caution. Also stay on trail. Our protagonists seem to stroll off trail right after finding the carcass considering they were constantly brushing branches, etc. off their face with no discernible trail.
Most bears if they hear that bell coming or a noise they'll move out quickly. Startling them generally means they attack. The whistle really doesn't work in that regard other than singling to someone else where you are. The bell is constantly dinging so as to alert them continuously to your presence.
Seemed like some pretty amateur mistakes by Alex who was supposedly good in the wilderness and in hiking those areas before must've been familiar with bears.