When Kat finds out that Richie ran over Lina:
Kat: [after Richie admits he ran over Lina] You ran over my sister?
Ethan: Look, look... it was obviously an accident. OK?
Kat: You're right, you're right, you're right. It's not his fault at all. No, I mean, if only they could put a reflective surface inside the car so you could see what's behind you!