MTD,
I think maybe you are visualizing the play differently than I am.
From the original post, I see dribble, slight brush up against defender, loss of ball, step out-of-bounds, step back in-bounds, resume dribble.
I agree with Dan, if no interrupted dribble, it's OB violation all the way. Otherwise, tough luck for defender.
I may not know a darn thing about over-and-back
(see bktballref's quiz)
but I think I got this one okay.