Just kiting, not launching. Basically a reverse with out being clipped in and holding the riser in my hands. I do this every time to check the lines and setup the wing.
Ever since I started ground handling to this very day I get the flip from time to time and every time I ask myself "Why, what am I doing wrong?"
I get my mistake if it just falls to the side, stalls, overshoots etc, but never figured out the "flip".
Could it be just a case of sudden wind direction change / gust? I've had this happen so many times I don't think it's likely. As I said, I always have streamers with me so I shouldn't be off more than 10-15 degrees at most to the prevailing wind.