Amber,

The question is: where did you LEAVE the skidmarks? and when did Toby see them?

I have run aground at full speed too, many times.
It's hard spinning and not pulling on the bar, but with enough experience wiping out, you learn. It might be best to just let go of the bar and let the kite go limp. Hope you are alright.
Donna got whacked big time once while just learning as well. She was on a C kite and it went from about 12 to solid 20 in a heartbeat, lofting her and then drilling her with a kiteloop. Stuff happens, but it is usually a lot less gruesome on a non-C, especially if you sheet out.