Thank you, Steve86. What is a horizontal groundloop?
Just spinning around horizontally on the ground. It spun at least 180 degrees.
A U-turn.
After all that discussion yesterday a newly video shows the fuselage at about a 45 degree angle to the ground during the groundloop (with one wing high). So, if you were at the right angle it might have appeared to be a cartwheel, even if not the case technically.
BTW, does anyone know if the missing engine (port or starboard) ever turned up?