Crazy stuff can happen. I have nicked my own leader lines with both snowboard and skis. Same scenario both times, I crash landed, got discombobulated, and noticed my leaders wrapped around my planks as the kite powered up. On one of those times, I did the damage myself by trying to be in a hurry, I ended up putting more pressure against it and kicked it harder.
Never had damage while sitting there, as there is little or no tension on the lines, but I do watch out for it, as it seems leery to have kite lines hanging over freshly tuned board edges.
I have witnessed 2 occasions where kite lines were cut while jumping. One was a boarder doing a rally, turned into the 'killer scorpion' move and he cut his own lines with his board over his head.
Next one was me, and quite embarrassing. It was at the first Mammoth Kite Daze, I was flying a Razor on handles (no bars for Ozone back then) and did some goofy jump in front of the Red Bull tent. I went inverted and poked my legs straight out above me, and basically pushed my board against my own lines. Subsequently cutting a control line, sending the kite into a death spiral on and around the RB tent.
Around that era I think James Brown started riding with several feet of plastic tubing around the leaders and kite lines near the control bar.