The rules of pretzel as explained in another by NS member Fink:
A pretzel is when you change your spin direction spinning out after 180 degrees or more of prior rotation.. as in spin on or swap. This makes the trick in the video a fs 270 out not a pretzel 270 out. You would think that with how much the term is embedded in skiing it would be universally understood, however I guess it's popularity is still only 4 or 5 years old.