retarding A/Ts
Rhythm method -
how does the NG autosystem work.. are you sure they would have to be actually making an automatic approach for the thrust levers to go into 'retard mode' at 28' ??
If they were making a manual approach with the flight directors in an Approach mode - would the thrust levers not close regardless if the A/T was engaged ? - you then have the question of whether the Rad Alt was possibly giving an incorrect reading..