It's probably from Turner's years in a New Jersey covers band (Ezra or whatever their name was), he's real good at emulating other people, doing different styles, too good sometimes.
Just listen to him doing the singer/songwriter thing here at 3.00:
This stuff is real rare, I never knew that anything of his career pre-Fandango existed, much less on youtube. And better still: The Ezra bassist plays an EB so it's all VERY connected!
Not stray from subjects we must.