I had a similar experience on Ryanair. A very large woman sat down behind me or tried to sit down behind me. As she squeezed and twisted and pushed to get out of the aisles.... she pulled and pulled on my seat.... (did I say VERY LARGE?) until she broke my seat and back I went. I got up and changed seats. Then.... the VERY LARGE woman broke the seat she was in and they finally moved her to the back of the plane in the very last row up against the wall. She really cost the airline for her seat.