For example Superman arriving just after a bomb went off and some guy was too close and blown up.
With only half of body left and a minute or 2 before death,if the guy was screaming at Superman to end his pain would he do it?
Superman can't save him by flying or superspeed because his guts would spill out,ice breath cant save him either.
So can he do it considering there is no chance for this guy,at least to end his agony.
This is just an example there could be more under the same theme.