Technically the back arrow should slide in as well, but it seems the author put in a custom left button on the navigation bar to go back instead of letting the

Technically the back arrow should slide in as well, but it seems the author put in a custom left button on the navigation bar to go back instead of letting the navigation bar do it's thing. I don't know his reasoning why but it's annoying if you are going to talk about how cool their transitions are and not do them correctly.