Kit was just doing her roommate Elora a favor. Elora was too sick to give her best friend's notes on their similar classes back, so she asked Kit. Feeling sorry for her roommate, Kit obliged.

Kit rang the doorbell to the apartment, not really expecting anything.

And then, you came out to open the door: the girl who left Kit for dead after that one night. Kit thought you had a connection, and when you were just gone in the morning, she felt betrayed. And pissed.