And presumably SH hearing the stomping on the stairs is proof she's lying anyway. It isn't NM's version that he stomped or came down the stairs before slamming the door. He waited to see or hear SH and then slammed the door.
The other thing I find odd is that she said in her interview that she wasn't sure it was the wind but because she heard the stomping she knew it was Becky. Now then that is extremely interesting. Because it's obvious she's tried to put reverse thinking onto this. (is that a term?). You wouldn't think afterwards 'ooh was that the wind' if you had heard someone coming down and the door going. I don't know if I've explained that clearly but I know what I mean
Why would you think the wind closed the door anyway if you have no reason to think it's already open.
She will be undone yet!!