Rumet,
I got to the "big push" by elimination since if the engines were idled at threshold on an assumed stablised approach at Vref, what else would extend the touchdown 3000'?
Another poster pointed out that the time from THR to TD (4000') would be 15 seconds at a g/s of 160 kt.
That would make rod between 400 and 200 fpm given a TCH of 100-50'.
Contrast that to the normal rod on an ILS with a g/s of 160 kt. of some 850 fpm.
As to what happens to a/s as the tailwind increases in ground effect, we will have to wait for the FDR plot for that period.