I think he's still likely to destroy her career, as a necessary result of re-establishing his own. He was very clear he wanted it televised and for good reason - he needs the world to see what BPD looks like in practice and it was a smart move.
I have also seen career's destroyed on false information - and yes, once the damage is done, it cannot be undone. In a world where accusation alone is enough to provoke a kneejerk response from a company - that company should also bear some of the cost of their position. Depp won't be able to sue Disney - because they'll cite 'creative differences' or a 'morality clause' - and it'll be legally enforceable. But I do hope he comes out swinging at Disney.
That mouse needs to be absolutely bitchslapped into a better form of accountability.