The honest answer is, which you avoided, is that the NIST looked dilligently to find ANY steel that reached temps that would weaken it. THEY DIDNT AND COULDNT.
No, you missed the point. NIST was looking for identifiable steel. Don't forget, much of the damage to the steel recovered was determined to be the result of the collapse, not necessarily the conditions before collapse. NIST cataloged the steel that showed evidence of several different types of damage, but with no way to tell exactly where the steel was located, it is impossible to determine the exact cause of the damage.
Since there was plenty of other evidence for the fire temperatures, steel showing the effects of those temperatures would have been redundant.
It would be like investigating a car accident, determining the brakes failed, and then saying "Aha! Since you didn't check the status of the rear brake lights, there has to be another explanation."
In lieu of the above fact, they again morphed the story to dislodged fireproofing as the culprit.
Because previous lies werent justifiable in relation to OBSERVED TEMPS.
What lies?
There is a perfect reason why NIST continued to change its story on the collapses.
Sure, additional evidence is always a good reason to change a theory.
They dont stand scrutiny, and they are well aware of it.
Thank god we now have a shotgun shot into a box to explain how dislodged fireproofing is the newest culprit.
Just like a common criminal who continually changes his story and whereabouts while being questioned by police, becuase he figures a new lie will finally clear him, so the NIST has went down the same path.
They are unfortunately being asked to stand on an untenable slippery slope, and thus far have found little to no purchase on this slippery slope, which is the "Official lie"...Sucks to be them.
The NIST is exactly this...The poor lawyer being asked to defend for murder a client they are well aware is guilty.
Since when did the NIST report become a criminal investigation?
As a source of recommendations for improvements in building codes, it only makes sense to investigate possible contributing causes to the collapse in order to update building codes to avoid such failures in the future. In most cases, NIST is tasked to make such recommendations based on any available evidence. They are not tasked to prove beyond all doubt what exactly happened (that is the job of a criminal investigation), but to determine plausible and testable theories that can improve building practices.
And before this gets dragged out again, I do not think the NIST report is perfect in any sense. There are a couple of their code change recommendations I do not agree with, and there have been plenty of other papers and tests done that disagree with some of NIST's findings. However, that does not suggest in any way that they "FAILED" at the task to which they were set.
It is the truth movement that fails to understand the nature of the report, not the report that fails to meet its mission.