Earlier quoted context omitted.
In real life scenarios there is a built in uncertainty with doing an action. Imagine a scenario where you redirect the trolley to kill someone but the people you wanted to save would have survived anyway.
You could imply that this uncertainty also exists in the trolly problem or you could imply that it does not exist there.
For one thing, in the real world if the trolley is close and moving fast then you have little time to think and observe and high uncertainty, but if the trolley is distant and slow then you have lots of time to try calling other bystanders, untie or rescue people from the track instead. So the more your choice is constrained down to just moving the lever or not, the higher uncertainty and less clear the situation is.
And in the real world it's more likely that a group of young people would tie some shop mannekins to a track for a laugh, or a film studio would tie props to a track, than that a moustache-twirling villain would tie some real people to a track. There is uncertainty in simply believing what you see; seeing five people tied to train tracks and about to die and being convinced they are real people, would have me thinking I must be dreaming.