Interestingly Zlin has 8000 hours on the 777 and cannot understand why the thrust levers did not maintain the speed. I am sure he has never been in FLCH down to touchdown, quite rightly as that is not a mode you want to be in, but if you were to do that the autothrottle will not maintain speed in that mode if the pitch is manually increased to a pitch above the flight director command.
Having seen this exact scenario of getting low and slow in the 777 expertly demonstrated in the simulator a few times over the years as a warning I would like to make a few comments and explain a few points to those aviation enthusiasts who are having difficulty understanding how it can happen.
You have to have the exact combination of being too high, too fast, rate of descent reducing, speed reducing, autothrottle in hold mode. You have to simultaneously intercept the appropriate 3 degree profile from above and have the speed at Vref and decreasing at about 500 feet. At that point it looks ok as regards height and speed but it goes wrong terribly quickly. If the Asiana had had the stick shaker 20 seconds earlier they could probably have successfully gone around, 20 seconds later and they would have been on the runway having had a heavy landing.
When manually flying the 777 there are still many automatic functions helping you. For instance if you roll into a 25 degree angle of bank there is no need to increase the back pressure on the elevator. If you increase the power the nose will not pitch up. If you are flying a visual circuit you do not need to advance or retard the thrust levers manually at any stage. This is all designed to make it easier to hand fly but it does erode basic flying skills.
The NTSB comments were very much what I was expecting. It is quite difficult to crash a serviceable 777 in good weather but there is one way for a pilot inexperienced on type to do it. Start the approach high and fast in FLCH with 0000 in the alt sel. Do not conform with stabilised approach criteria at 1000 feet, Regain the visual glideslope and Vref at about 500 feet and do not change the mode. The speed and height will drop off very quickly. I think unfortunately they discovered this method.