Replying to Flatspin Turning Into Bio

Ok so the other day i tried a flatspin......I can do them on the tramp very well so when i got to the jump i felt pretty confident on the in air motion. I came up feet shoulder width apart popped not that hard probably could've popped harder threw my shoulders the way i did on a tramp and ended up doing like a horizontal spin bio misty shit i don't even know. My theory is with the boots and skis on my feet didnt go with my shoulders so they just stayed beneath me and my top half just spinned out. If You dont agree with my theory please tell me yours and how to fix it like a better technique
Thank you