The debate became a credible threat

I fail to see how this is the case. The existence of the shoddy pull request and not-so-secret private discussion make it less likely there's a secret competent cabal waiting to surprise fork out Steemit Inc., not more. Up until this point there was always the possibility that someone was doing that in the background and no one knew. Now there pretty much isn't.

In this scenario, I fail to see how Ned had an opportunity to realize anything tangible one way or the other.

Taking a major action in that scenario, especially one that had minimal immediate effect, is pretty much the definition of over-reacting, then, no?

On the other end, something had to deescalate, so that's why you're now seeing it all plastered on the blockchain

Top witnesses making unsubtle implications of getting together and launching an independent fork in an attempt to force Steemit to do what they want with its stake isn't exactly de-escalation.

They've put Ned into a position where stopping the power-down would be acknowledging that the witnesses have a right to a say in how Steemit Inc. uses its funds. As a corporate officer he can't do that; it's malfeasance. The only way out of this now is for them to back down.