Once again, "Richard's" mind-reading skills underwhelm. She said nothing about lights ON THE PHONE. And why would people wanting to order school books from across the state of Texas stop calling because a motorcade was coming near her building?
Besides that, Deputy Mooney also mentioned that the power had been cut.
This is Mooney from his 11/23/1963 DCSD report:
"As the elevator started up, we went up one floor and the power to the elevator was cut off"
His WC testimony follows along the same lines:
"It was a push button affair the best I can remember. got hold of the controls and it worked. We started up and got to the second. I was going to let them off and go on up. And when we got there, the power undoubtedly cut off, because we had no more power on the elevator."
So, there was power until Mooney got on the elevator and had ascended from the ground floor to the second. And he said that power cut only for the elevator. He didn't say it was building-wide.
BTW, it should be noted that Mooney didn't enter the building until after 12:40. In sum, there is nothing whatsoever in Mooney's testimony that supports your interpretation of Hines' testimony.
As for "She said nothing about lights ON THE PHONE," it's worth pointing out that she also said nothing about THE BUILDING LIGHTING going out, or about ELECTRICAL POWER BEING CUT OFF, or any number of other things expressed in ALL CAPS. Nor is there any good reason to think that she wasn't referring to lights on the phone. I don't know if you're old enough to remember, but most businesses used multi-line phones with a row of lighted buttons along the bottom. Each lighted button represented one line. When the line was being used, the light corresponding to that line would illuminate. When the call ended, the little light would go out. So there's nothing odd, wrong, or illogical about the interpretation that Hine was referring to the line active lights on the multiline phone right in front of her.