It looks to me like your setting for a 5 and whipping the last little 180 around super quick hence the landing backseat. I think if you set harder and lined up properly with the landing you could stop.
I don't think the last minute 180 is getting you backseat, however i do think your not spotting your landing your legs don't know when to stiffen until they actually feel the ground.. if you spot your landing you can get ready for it in the air and stomp it. If you can spot your landing earlier i i think it will also give you time to adjust a little in the air.
Ok so i rode up the chair with a ski coach that is best friends with tom wallisch, and the reason why tom looks so good when he is spinning and landing is because he always has his hands right in front of him so his arms are never playing ketchup, that little advice helps me stomp my 7s so just try to pop a little harder and just keep looking over your shoulder.