Reply #122: The thing I found interesting

[LARED]

is the ARUP reviewed the NIST's work. Something that shows the NIST is acting above board. It is quite common and desirable to have a design validation of engineering work.

Note the article here http://www.csemag.com/article/CA6263555.html?industryid=23442 states

Arup commended the work of NIST to model the WTC collapse—a vast undertaking. However, Arup's review of NIST's findings and its own analysis led it to conclude that NIST has not satisfactorily demonstrated its main conclusion but that the impact-induced loss of fireproofing was the deciding factor in the collapse.

....

Arup’s analysis concluded that the effect of thermal expansion on the perimeter columns of the towers—even without the airplane impact—could have led to collapse due to the severity of fire occurring on multiple floors and the resulting thermal expansion of structural elements, particularly the floor systems. The Arup analysis conclusively illustrates that even with code-approved fire protection, a severe fire—without aircraft impact—could still lead to collapse.

Basically they are saying they think the NIST's work was not detailed enough and did not take one important parameter into consideration (in the view of the ARUP). It's a bit of a stretch to say they are calling it faulty, as if it completely missed the mark. I would categorize their criticism as simply stating the model could be more accurate and useful to future design codes.