When Kara hears Cat saying," I don't have an attitude problem, you have a perception problem," there is a close up of her ear and there is no stud in her earlobe, when Kara turns around, the stud can be seen. However this is due to the way her earlobe is angled to the camera, it covers up her earring, making it look as though she's not wearing them. Having said that Kara should not have pierced ears anyway, since nothing can penetrate her skin.
When Maxwell Lord is talking to James while they're walking, you can see the camera, and camera crane in the building windows reflection behind them.
General Lane wears the 4 star insignia of a General, but also wears the emblem of the Black Horse Division. A division is generally commanded by 2-star, Major-General, so Lane should either be of a lower grade or should not wear a divisional Command patch.