"The OPT offered the crew only one option for Runway 09, which was ‘09#T1’ as displayed by the OPT. This was understood by the crews to mean Runway 09 full length, although the performance data had been pre-modified by a temporary NOTAM."
Seems pretty clear to me, the crew thought they were going for full length, but then saw T1 and mistook it for taxiway T1