That last statement could apply equally well to Kav. Indeed, his having the power of the President (remember Kav's being holed up for two or three days at the WH for questioning preparation?) and the GOP *majority* behind him in their steadfast backing, and knowing that an FBI background check extension was to be nixed at all costs, he good reason to believe he could lie with no consequence.
But in spite of that, he was nonetheless too gutless to go all in and clamor for an unbiased investigation. Because he knew that would have forced the Goopers' hand, and that would bring everything crashing down.
On the other side, what could Ford count on to shield her from lying? A Dem *minority* that looked to be unable to stop the ultimate ramrodding through of Kav. If the *full* FBI investigation she and the minority were insisting upon from the start did actually come to pass, she could be in a bad place for having made so certain a false allegation.
In the end, who between Kav and Ford had the most to lose by lying? For Kav it's just that he'd stay at his current post. For Ford it could be a criminal charge.
And who has the most to gain by lying? Kav gets his fervent ambition realized. Ford goes back to her daily life, hopefully with the harrassment and death threats subsiding.