Why reknors do not know reinforcement recording time ?

[samsocial]

In chapter 13 of steel heart, reinforcement starts. David tells us that it is prerecorded and we don't know when it was recorded.

In same recording steel heart destroys multiple buildings. Why then it is not possible for anyone to know the time of recording. It was definitely done when those buildings were destroyed, right? Why rekners could not backtrack and find the exact date and time? Why in the first place they did not know anything about destruction of these buildings?

[EmulatonStromenkiin he/him]

big city, lack of information, police.