Involvement in the world isn't voluntary; actions have consequences, some people prefer some consequences to other consequences.

In your case you value maintaining an unsullied self-image over assisting 5 people in mortal peril, and would prefer if other people saw your choice the same way.

But you're right (I've met people who were familiar with the people involved here): the intuition is that the stronger the perceived interpersonal relationship between you and the unlucky bloke the less likely you are to flick the switch, but teasing out exactly how much relationship is needed to make the moral intuition flip is tricky business.