That is a good question. If they had reported that the FBI was reviewing Flynn's phone calls and that Flynn and Trump reported the conversations were innocent, that would be one thing. But they jumped to impeachment. I imagine to get more progressive clicks to generate more ad revenue and sell more goods for their corporate sponsors, no doubt.

Now, I suppose, if confronted with the truth, they need to report it? Better for them would have been to ignore the story and continued down the impeachment / obstruction of justice Russia-hysteria road. But I guess, a point arrives that the facts look so settled there is no way to spin them? Don't know?

But as you pointed out, it is the WaPo, so the whole "clearing Flynn" could just be another un-sourced canard. Who really knows?

Sadly, the upshot of all this is that it seems we are now having real problems with Russia as they have vowed to shoot down US planes west of the Euphrates. Trump campaigned on a detente with Russia, but is helpless to execute it due to the Russia collusion fabrication. Apparently, no progressives thought about the consequences of the falsely generated Russia-hysterics, typical.