When a suspect who is confronted with a direct question repeatedly tries to change the subject and refuses to answer the question, that's evidence that he's guilty.
For example, if a suspect is repeatedly asked "did you stab Mr. Roberts?", and he replies "I didn't take the money!" every time he is asked, that is proof that he did in fact stab Mr. Roberts. That's especially true if no one asked him whether he took any money.
NIST is doing the exact same thing in regards to the basic questions which 9/11 activists keep asking.
For example, NIST's new factsheet contains the following question and response:
2. Were the basic principles of conservation of momentum and energy satisfied in NIST's analysis of the structural response of the towers to the aircraft impact and the fires?
Yes. The basic principles of conservation of momentum and conservation of energy were satisfied in these analyses.
In the case of the aircraft impact analyses, which involved a moving aircraft (velocity) and an initially stationary building, the analysis did, indeed, account for conservation of momentum and energy (kinetic energy, strain energy).
After each tower had finished oscillating from the aircraft impact, the subsequent degradation of the structure involved only minute (essentially zero) velocities. Thus, a static analysis of the structural response and collapse initiation was appropriate. Since the velocities were zero and since momentum is equal to mass times velocity, the momentum terms also equaled zero and therefore dropped out of the governing equations. The analyses accounted for conservation of energy.
What NIST is saying is that -- when the airplanes hit -- the Towers oscillated for a short time, and then the movement quieted down, so that NIST didn't have to account for the movement in its analysis.
But that's not the question that 9/11 victim's family members, scientists, engineers, architects, military leaders and lawyers are asking. When 9/11 activists talk about "conservation of momentum" or "conservation of energy", they're not talking about the oscillation from the plane impacts.
What they're referring to is:
(1) The speed of the collapses of WTC 1, 2 and 7 should have been slowed much more than actually observed by the still-intact portion of the buildings below the collapse zones; and
(2) Once the upper 30-story block of the South Tower started toppling over sideways, it should have continued to fall sideways well away from the base of the South Tower.
See Dr. Steven Jones' paper for details.
In other words, 9/11 activists have been asking a very clear and direct question:
"Aren't explosives necessary to explain why WTC 1, 2 and 7 collapsed at virtually free-fall speeds, and why the upper block of the South Tower started toppling over and then straightened itself out during the last phases of the collapse?"
NIST's response that the oscillations from the plane impacts soon straightened out is answering a totally different question. The fact that NIST is answering a question referring to something that occurred around an hour before the collapses -- which is what the 9/11 activsts' question refers to -- shows that NIST is intentionally avoiding a direct question. NIST is, in essence, saying "I didn't take the money", when we've been asking " whether Mr. Roberts was stabbed.
In addition, everyone knows that when a witness is caught lying or changing his testimony, it effectively discredits him. If the witness is himself the accused criminal, then perjury, inconsistent testimony or destroying evidence tends to implicate the defendant's guilt. See this and this.
An agency trying to accurately research what really happened would not destroy evidence, falsify results, and repeatedly try to change the topic by addressing straw men and red herrings.
