must be slight movement forward that the flash did not stop, why it looks cut out is the dark edge behind it's tail
I don;t think you need to do anything.. it is what it is...

No, not cut out at all, so what should I do then?

I looked at this a few days ago...
I noticed it then and noticing it now
she looks cut out and pasted into the background. Is she?

cool shot light wise!

This is fantastic -- he looks all golden and ruffled and shimmery.