It's been set up so far to suggest that if Kate was having an affair with anyone, it’s Simon the hearts her. Who btw has a gorgeous wife who looks like Kate. I don’t think that necessarily means that they were having an affair; I like a PP’s suggestion that they’d been an item when younger and so had a connection.
Good spot on the “what’s she done” @FlamingOranges I think he probably did mean Kate but it’s got me wondering about his mother, Carol, who Kate has called (or someone using Kate’s phone ...)
Btw the pine needles were only found in one girl’s feet - Iris I think but could have been Emily.