There's just that one dark strand slightly above the focal point where part of it is blurred and part not. It looks kind of choppy. It downs on me that this might be intentional as most of your pieces are usually pretty distorted(in a good way).
ahh i think i know what you mean, choppy as in, sharp edge, quite hard/choppy. Thats usually what I get when I use lens blur filter, but its usually less evident because I render at a huge res then scale down, this one is rendered to 1680x1080 so its a lot more evident.. I am not sure about why that is happening..