Most misinterpretation of the last two pages stems from the sentence
"the authrottle went to "retard" mode and the throttles then stayed at idle"
Most of you mean that it went somehow into an autoland mode.
This isn't necessarily so. AT can also go into retard mode if speed demand is lower than actual. This is the case in LVLCH mode or VNAV approach. 737 rated people please confirm. They were on the GS but that doesn't mean that their AP was tracking the GS! Two different things! If you check the ADS-B data you can see that they never accuratly tracked.
The most probable explanation is that they just forgot that they left the engines in idle. They were doing the checklist and maybe discussing other things. Get real, guys. See the obvious!
And again, the only thing they did wrong was not doing a Go-Around at 1000ft.
Dani