Actually, I do know what Hess and Jennings meant because I listened to them. I am sure just about everyone has heard the Jennings interview. However, this Hess audio interview is what I found about a month ago. In it he stated exactly why they descended WTC7, and that was because of the lights going out in the building due to the power failure.
This is what I wanted you to hear in my link.
However, just now I rechecked that link and it has become broken. This is unfortunate. This short interview, the only one I ever ran across by Hess, is now gone due to the vagaries of the internet. A bit frustrating, but on further reflection not really, for I now realize that even if you had heard Hess say these illuminating words, you no doubt would say he is only covering for Giuliani (whom he now works with at Giuliani Partners) and other "conspirators".