I think he returned somehow...On this page
http://www.mangahere.com/manga/naruto/v60/c608/9.html
AND this one: http://www.mangahere.com/manga/naruto/v60/c608/12.html, you can see the fight going on in the background
kakashi used kamui on himself. I guess he figured the properties must be the same as obito. If you kamui something it gets sent to the dimension. But if u use it while in the dimension, it must be sent back to the normal reality