It's abundantly clear why she spiked it. I know it. You know it. We all know it. She was brought in as a clearly partisan voice to put exactly this finger on exactly these levers at CBS. We all saw it when she was hired and we all warned about this. And she did.
I mean, why bother stenographising the excuse? No one is fooled. "Partisan hack does partisan hackery" is like the least surprising line in this story.
Plausible deniability, so that people on one side have something they can use.
(Obviously we believe it isn't plausible, but that doesn't matter in these sort of things)