Shelter from the Storm - S3-E18
Continuity mistake: When Winn and Brainy hug, Winn starts the hug with one arm high and one lower, towards Brainy's waist. The shot cuts and both his arms are up and in the centre of his body.
Continuity mistake: The shield design that Winn sketches on the paper changes between him starting to draw, and him showing it to his friend a second later.
Continuity mistake: The sketch that Brainy shows to Winn is meant to be his original sketch that he drew in the previous episode, hence why Winn is so shocked he's somehow got it. But it's slightly different from what we actually saw him draw at the time.
Continuity mistake: During the fight between Supergirl and her clone, the clone blasts Supergirl with her purple lightning power, which causes a small explosion and also somehow turns the sky from bright dusk to nighttime.
Crisis on Infinite Earths: Part One - S5-E9
Continuity mistake: Oliver still has a quiver full of arrows when he's making his stand at the end. A shadow demon knocks him down and all of the arrows disappear instantly. They've not been knocked out of the quiver onto the ground, they've disappeared entirely.
Continuity mistake: Kara and William review the article William has written about hate crimes against the transgender community. The article text is shown, and it states that Yvette's attacker, Gregory Bauer, was arrested. But Gregory is not identified and arrested until Dreamer confronts him that night.
Answer: Yes, s02e22. As Kara leaves her office, she said "go get them, Supergirl" to herself. After season 1, the show switched from a CBS production to a CW production and filming moved from L.A. to Vancouver. Flockhart isn't really a fan of traveling to shoot, and didn't want to be away from her family for so long.
Bishop73