When Kara is hovering over the DEO trucks, the agents begin to shoot her with green bullets, presumably Kryptonite. The bullets seem to have no effect on her. This is either an editing mistake or a way of saying that while under the influence of Red Kryptonite, they are immune from the green.
At exactly 11:51-2, when supergirl was fighting k'hund. The mic was clearly visible.
James and Winn go to the DEO headquarters and announce in front if everyone that Kara is having problems, thus outing Supergirl's secret identity to every one in the room at the time.
At about 26:20 Cat says she knows Winn and James are trying to cure Supergirl when she can't know that Supergirl is sick or infected with red Kryptonite or that they would be involved in a cure.