I called scud at the time, though have been wavering thinking it more based on our location on the radar (we did not have radar with us on the chase ... just on my phone, which is low on detail), and also based on using the progress bar to speed the video up. Slight rotation can be seen. The only certainty was that it was a pocket of rapidly ascending air under the wall.
What do you think?
(location on radar indicated by red arrow: click for larger image)
Here is a screen cap from earlier video of the wall cloud (before we basically drove under it).