I won't name names, but once upon a time I watched two extremely experienced and competent pilots fly a Grob 103 right off the end of the landing area at CCSC and into head high weeds and brush. Both thought the other was flying. Not sure where the handoff was botched since the glider flew a normal looking pattern and approach. Took the rest of the day to get the milkweed sap off the canopy and nose of the glider.