Now that I'm thinking about it more, based on his appearance he might have already relinquished some control, or he mastered his tailed beast in one shot! That would be such a crap move, considering it took other Jinchuuriki a bit of time to make "friends" with their tailed-beasts.

He could have also stole the tailed-breasts powers like Naruto did initially, but then again, that usually involves a process.

I might be over thinking this again, almost like I did 371. I can't wait to see how this plays out!