[Through leaning on the nearby wall, she's able to stand without worrying about her legs giving way underneath her, continuing to rub her throat.]

Seeing something and making a mistake is one thing-- but you could've had the decency to apologize for it! [Of all the things to potentially be injured, her throat-- her voice-- is a frightening one.]

"I'm so sorry, I thought you were someone else, are you all right? I didn't hurt you, did I?" [She says, affecting a tone to make it clear she's trying to voice the other woman.] If you'd just said that in the first place we wouldn't have this problem.