In your use case, only the poster could do it.  Nobody could rug-pull Darth except Darth.

But could a bad actor do a misleading switcheroo on his own content?  I suppose so, in theory.  In practice, would anyone bother?  Maybe.  What could happen in response?  Well, there would be the edit history demonstrating his bad actor-ness.

But yes, I think you could come up with a situation where something you didn't like would happen.

elvismercury

It takes a joker like me to realise the possibilities of this - and someone like me would play merry hell with this.

Bitman

Feature idea: perpetually-editable SN posts

I like giving new things a go, but couldn't someone abuse this though...

If I've got it right, couldn't a troublemaker could write gushingly about Bitcoin, get lots of comments and do the ol' switcheroo and it looks like someone like Darth has been giving Doge the thumbs up.

If I'm right, it could cause a lot of trouble. Lots of Rickrolls too.