I have read the report thank you, and I did see that it used reduced power. And I see no evidence that they increased power once airborne.
However if you look at my post, I am suggesting that even had they firewalled it... as "JNB is hot and high. They were very close to MAX ToW and there would have been little or no extra left."
The report states:
The Maximum Certified Mass for the aircraft is 396 890 kg and the
Take-off Weight for the aircraft at the time was 365 000 kg. The
aircraft was thus 31 893 kg below the Maximum Certified Mass
during take off
However what it does not say is what the
performance limiting weight was. It was probably below 396,890kg. The ATIS wind was light and variable so odds are that they used a tailwind in the take off performance calculation. If they did then they will have been very close to the performance limit.
I take your point, but having flown the 744 for a while and flown the exact departure at JNB in similar conditions, they will have had little extra performance available.
As a PS: The engines on the 744-436 can be safely firewalled. They have a fancy computer between the thrust levers and the engine and if you push the TLs fully forward the computer will give you maximum available power whatever phase of the flight.