Then nature of the thought experiment is that the variables are set in place. There is no chance that either group would notice the train, the specific group will die in its entirety if the train is headed towards them. Similarly, the train will not derail if he chooses to switch the track, it will head towards the group of 5 and kill them. The point is to get rid of those contingent, context-specific factor and really hone in on the matter at hand, does he kill the group of 5 or let the 40 die? You say this, and it's a perfectly agreeable statement. But is it not also true that by being there, knowing the consequences and having the capability to make a decision, that he is responsible either way? He is choosing who will die whether he pulls the lever or not. A person is responsible for what they choose not to do as much as what they choose to do.Greg should not direct the train towards the five people the train is not already heading for. This would be Greg causing harm.