If I might clear something up for both sides...
The "low order of probability" comment comes from the FEMA investigation of WTC 7. NIST has never said any such thing. The FEMA report was completed years ago, and is quite cursory. The NIST report, as most are aware, has been repeatedly delayed as its scope has grown, and is now anticipated towards the end of this year.
FEMA did indeed state that their proposed collapse hypothesis was of "a low probability of occurrence." However, the report needs to be read in order to understand what that statement means. FEMA's words, in context, are as follows:
Originally Posted by FEMA
These scenarios involve a large number of steps. All the steps appear plausible, but FEMA was unable to properly investigate how the fueling system worked, etc., so the scenarios above were largely hypothetical at the time FEMA wrote it. If we were to investigate those steps, and find that FEMA's speculation was in fact predicted, then the scenarios would immediately go from "a low probability of occurrence" to a "high order of probability." This is part of NIST's investigation.
Also, since the FEMA report was published, we have learned much more about WTC 7:
- The amount of damage caused by WTC 1's collapse has been understood to be much greater than previously thought
- We have a better understanding of the collapse initiation
- Many more videos of both impacts and collapse have been recovered
- NIST has done an in-depth study of the emergency fueling systems
What this all goes to show is that you have to actually read
the FEMA report to know what it contains. It is a very limited report, limited by time, money, and access. FEMA admits as much. There is no reason to take their statements -- that they could only propose speculative scenarios, and that such would be considered improbable without further work -- out of context.
If one really wants to understand, I suggest one go to the source.