in my opinion its both the bases and the flyers fault. After watching the video and analyzing the incident i notice in the other two groups their flyers land with their head toward the back of the floor and the center flyer who fell her head was toward the front of the floor, so the bases obviously were expecting her to land the other way and were not prepared for the way she landed, so in that case its the flyer and the bases fault; the flyer didnt do her job and the bases didnt do their job, its not just ones fault.