Captain America is fighting a bad guy, who finally has enough. He tries to blow Cap up, but Scarlet Witch steps in to save the day … or does she? In this case we see that superhero fights can impose externalities on those they are trying to protect.
When superheroes try to save the day, there is almost always collateral damage. Those innocent bystanders are the third parties who are caught in the crossfire. Sometimes the negative externalities imposed on them are minor such as getting to work late due to a hero/villain fight on the subway. Other times, as we see here, the harm is much greater.
