Seems pretty clear to me, the crew thought they were going for full length, but then saw T1 and mistook it for taxiway T1
OK, so you are saying that the "#T1" designation stood for temporary NOTAM, not for T1 Intersection. I understand that, and it seems the crew understood that by the statement:
This was understood by the crews to mean Runway 09 full length,
But it still does not explain what the temporary NOTAM was. And it sounds like the relief crew understood this was not full length but did not intervene. Surprised they allowed their concerns to be dismissed with a hand wave.
Takeoff performance procedures are often written in blood or very brown shorts, as they soon found out.
Another thing, the timing does not seem right. It shows Miami being only 6hrs behind Doha. I thought it was 8hrs, making it 0412 time in the morning for the crew.