Getting to the root cause.....
Jump Seat 777. Well you certainly gave it to us. Well done - and thanks for taking all the time to put that lot together. I must confess that as a mere ex-RAF and now PPL the shear/vortex theory met the description of violent banking and porpoising on late finals with high engine noise. Just goes to show how wrong one can be. Obviously the old adage "convert speed to height" whenever you can worked and full marks to the officer with hands on.
Looking forward to hearing the full story, especially what steps the flight deck took to remedy the problems as they arose arose. One question: was the lower than normal glide path due to reduced power or was more power demanded as final flap selected? Is final flap selected on the 777 earlier than 600 feet - especially in gusty conditions?