It has nothing to do with the first 180, it's all about the rotation pattern, inverted or not.
If you think that inverted is hips over head(which is the standard definition), that is a rodeo, as you can see as the persons feet are pointed back at the jump, the hips are slightly over the head and the feet are pointed to the sky.
In a flatspin, the hips and head are level, and the feet are pointed directly back.
To throw this trick flatter, don't do such a backflip-ish rotation, take that right shoulder and bring it more forward so you are facing the sky.