They need to do it now. Otherwise, they are all accomplices.
To my mind EVERY ONE of them is complicit already by the mere fact of not telling what they know or outright resigning in protest.
In my opinion not one agent will resign no matter how corrupt their beloved agency becomes and you are right if they know and do nothing they are complicit in the coverup and corruption and every bit as bad as their director and leadership.
I have heard for the longest time about how dedicated and professional and ethical these agents are yet when the crap hits the fan I hear crickets chirping from their direction. Put up or shut up special agents or otherwise be considered just a rotten as the ATF, IRS, VA, etc...