Lost Series 5 episode 11 Whatever happened happened

Roger and Kate are pulling the van out of the house when they see Jin screech up to the infirmary and carry the wounded Ben inside. Roger realizes it's his kid and runs over, following them inside. Kate watches in disbelief.

WHOOSH to three years ago as Kate pulls up to a suburban home with baby Aaron. She carries him to the front door and rings the bell. Cassidy answers and is thrilled to see Kate. Cassidy saw the news reports about Kate surviving the crash and told all her friends she knew that woman. But she never thought she'd see Kate again. Then she asks why Kate is there, and Kate tells her that Sawyer sent her.