If WaPo is the only one who can be held accountable and their only accountability is issuing a retraction, that seems like a gameable system.
I feel as a news org, the best you can do is just report the data as it becomes available. Obviously later data could contradict prior data or clarify its interpretation. What matters though is the accuracy of the data reported, not in the data being a perfect predictor of the outcome, but that this is accurately the current known data, even if it later comes to be shown incomplete or misleading.
Maybe don't report something that one person told you and that you can't otherwise confirm?
That used to be the way that news was done, right?
That seems like a bit of a rose colored view of news in the past.