the fact they were required to use only idle reverse thrust.
I don't believe that to be a correct statement. My reading of the ATSB report was that idle reverse was the standard mode as always subject to the Captain's operational judgement on the day. I also believe that report recorded that while 3 of the engines were in idle thrust (not idle reverse though and I'm told there is a significant difference), the other one of them was actually in forward thrust with the thrust lever advanced a knob or two.
I'm sure that the bright spark in management didn't decree that this configuration of thrust was the standard to be used on a dark rainy night.
I was also told that the PIC changing his mind and landing part the way through a missed approach wasn't standard company policy.