So, a 16 g seat on a 9 g seat track? Makes sense to me!
Well, it sort of does. Seat tracks and parts of the floor structure are prone to corrosion, so they have plenty of margin for blendout. Additionally the fllor structure is designed for the most dense seating arrangement. In perfect condition they stand much more than 9g, which is the limit load criteria. Ultimate load is at 13.5g and above, often even exceeding the 16g. The seats on the other hand are tested for their dynamic behavior at 16g, without margin.
I think the Asiana crash shows more collapsed 16g seats than broken 9g floor structure. But it will be nevertheless interesting to follow the investigations and to learn from it. This crash will make it into text books, for pilots and for engineers, end evertually into the rules as well.