Everyone present knew about the grudges between Ethan and Yale.
However, Olivia didn't restore her marriage with Ethan. It was clear that they were close.
She definitely didn't show up to help Yale. She was the one person present that didn't have any reason to lie.
She didn't speak ill of Krystal because of the grudge she had with her. Neither did she help her because Yale was Ethan's biggest rival.
She didn't know what lies Krystal and Lisa fed Mason. Regardless, Molly shouldn't be the sac