The point is the difference between the cases, not the answer to any one of them.
Most people say it is permissible to divert the trolley, killing one instead of five. Most of the same people say it is not permissible to push a large man off a bridge to stop it, killing one instead of five.
The numbers are identical. So whatever explains the difference is not a calculation about outcomes, and that is the finding.
Candidates are the doctrine of double effect, the distinction between using someone as a means and foreseeing harm to them, and the difference between redirecting a threat and introducing one. The scenario is artificial on purpose, to strip away everything except the variable being tested.
It is a controlled experiment on intuitions, not a policy proposal.