I didn't like that part. She should've been able to figure out a way to save him too. That's sort of Superman's trademark in the comics, the ability to find a way to save everyone even when it seems impossible, and I'd like to see Kara achieve the same standard.
Eh, it might be a trademark, but that doesn't always make it the best storytelling choice in my opinion. I think it's far more interesting to see superheroes operating in a world of hard choices and who aren't able to magically save the day every. single. time.
And when a character as traditionally wholesome as Superman or Supergirl is confronted with something like that, it's even
more interesting to watch.
Sure,
if it's plausible and justified that there really is no other choice. That's my issue. I'm not convinced that it was impossible for someone with Kryptonian powers to both stop the train and stop the bomber from blowing himself up. After all, she had a good five or ten seconds after the train stopped -- that should've been plenty of time for someone with superspeed to do something. If the writers have to cheat and pretend there's no solution when there actually is, then the "moral dilemma" doesn't work.
A classic case of this for me is
Star Trek: TNG's "The Most Toys." The premise there is to set Data up in a situation where he apparently decides he has no option but to kill the bad guy Fajo. He couldn't restrain Fajo manually because of an anti-android technobabble field being generated by a box on Fajo's belt so that Data couldn't get close enough to touch him, and the only weapon he had was a really nasty disintegrator gun, and we were supposed to accept that the only way Data could save an innocent life was to shoot and kill Fajo, but he was beamed to safety just at the crucial moment, and it was left unclear whether he'd actually pulled the trigger intentionally or not, but it was strongly implied that he had. But I never found that implication credible -- not for any moral or philosophical reason, but simply because I could immediately see a nonlethal option that the writer overlooked. Data could've simply shot the box on Fajo's belt that generated the field, even just grazed it in order to knock it out without hurting Fajo, and then he could've restrained Fajo. I saw that option easily, and Data's enormously smarter than I am, so he must've seen it too. Therefore, the pretense that he was forced into a situation with no nonlethal options failed for me, because there was one (to me) obvious option remaininng.
So that's my problem with "no other way" scenarios like this. Often, if you apply sufficient imagination and lateral thinking to the problem, you can
find another way. So if you want to convince me that there really is no other way, you have to rule out
all the possibilities, even the non-obvious ones. And I'm not convinced of that here. Supergirl just resigned herself to the assumption that she had to sacrifice him to save the rest. She didn't even try to find a way to save everyone, so I'm not convinced there was no way.
