Don't know if this has been mentioned before but it looks like there is
more than 1 party under review , Boeing also doesn't seem to be totally without blame
Boeing May Still Be Blamed In Asiana Airlines Crash: SFist
Boeing could still end up being on the hook for never having installed an aural warning system of low airspeed on the 777, a system which the NTSB had recommended the FAA look into requiring 10 years ago. Also, the NTSB is requesting data about any other aborted landings of 777s due to similar problems on approach, and data on the SFO runway itself.