“At present, the big guns of the US media are in the hands of people pushing a certain agenda. In the environment this creates, Meghan Markle must be believed, regardless of the obvious gaps in her account, because that serves the agenda."
Who are "the big guns,...the US media are in the hands of"? You don't know.
What is their "agenda"? You don't know.
And, especially if she's a proven liar, why must we ignore "the obvious gaps in [Meghan's] account" - for them? You don't know.