I don't think the Rams are under any obligation to let him go.
And I seriously doubt that GW has any real heartburn over Fisher being fired, although I'm sure who becomes the next HC does matter to him.
But there's no reasonable way that the Rams can hold Williams up from getting a new job for very long. They either have to hire a new HC in the next 4 or 5 days and get the word to either release GW or keep him. Not because there are any rules about it (so far as I know), but because it is the decent thing to do.
