None of this would've happened of course. They wouldn't have wasted a non renewable grenade on 2 people, they would've tied Joel up, etc, etc. Most narrative trolley problems would not actually happen IRL
All the things leading up to these inescapable trolley problems are choices made by the writers to create this dilemma, to make a compelling, thrilling story
They are as unrealistic as the "would you rather" party games, but they impact us more because of the story