Corrected entry: When Colonel Haley tells Brainy that she wants to take measures to prevent a disaster during the pro-alien march, he mentions the Women's March as one of a few successful peaceful protests that have taken place in the past. While it was a large event that many may have considered successful, the Women's March was mostly in response to Donald Trump's election as President of the United States in the real world. Since Olivia Marsdin was president on Earth 38 at the time and remained so until she resigned after being outed as an alien, it is unlikely that the Women's March would have still happened on their Earth. (00:20:00)
Correction: Brainy specifically said the words "The Women's March" when he mentioned three previous successful marches, and the other two he mentioned in the same sentence were the Freedom March (nickname for the March on Washington for Jobs and Freedom) and the Million Man March. While both the March for Women's Suffrage (actually named the Woman's Suffrage Procession and commonly known as the woman suffrage parade of 1913) and the March For Women's Lives appear in the disambiguation page of the article "Women's March" on Wikipedia, neither of them are commonly known as the Women's March and would more likely have been called by their official names. Considering that the show also bought up the southern border wall and other politically-charged incidents involving the Trump Administration that would be plot holes on Earth 38, it's more likely mentioning the Women's March was a deliberate mistake done as a political statement rather than just an oversight or referring to a different march that would have still happened on an alternate Earth where Trump was never president.
Corrected entry: Supergirl has X-ray vision, but never thinks to use it to figure out that Reign is really Samatha Arias under the mask.
Correction: They have not specified what the mask is made of. It is likely lined with a dense element, such as lead, which Supergirl cannot see through. Just because we've not seen her try, doesn't mean she hasn't.
Corrected entry: Teenage Kara has pierced ears, even though her skin is supposed to be impenetrable. (00:13:15)
Correction: Magnetic clip-on earrings exist, and can make the sort of dents in her ears which these seem to, due to the strength of magnet involved. Adult Kara also has the same earrings, as seen in the "previously on..." segment.
Correction: He's most likely referring to the march for women's suffrage in 1913, or the 2004 "March for Women's Lives", one of the largest protests in US history, which had no violent incidents.
Jon Sandys ★