Thanks for the replies guys!
Towkin, if you're referring to the person shooting the video, it was my 9-year-old son (I'm the kook in the dark-green and gray jacket waiting by the "SLOW" sign).
For what it's worth, he was only sideslipping to try to keep the camera steady and he only did it for two runs. He normally does turns. The reason I used his video was that it was quite a bit steadier than any of them I took because I just rode as I normally do when I recorded. Though if you were referring to my skidding turns, well, I'm working on them.
I don't think we did too much damage since most of the ice seemed to occur in the shadows on the surface at edges of the trail where people traveled.