Ouch. Dan Romer was dropped at the last minute then.
I guess they couldn't see his score working for the film while in editing. He must be a bit pissed off about it.
Perhaps he'll just use it in another film, which often happens with rejected soundtracks. Jerry Goldsmith's Innerspace soundtrack was originally The Right Stuff soundtrack, but was rejected.
Never heard of Dan Romer, looking at his back catalogue it does seem like Bond is a bit outside his wheelhouse and quite a step up from what he's done before - not necessarily a problem but big studios are always going to be cautious.
Hans Zimmer has an incredible track record, I still think his soundtrack for Inception is one of the greatest movie scores of all time.