Board Thread:Episode Discussion/@comment-14138255-20180109165438/@comment-26397825-20180110022538

Raven has a bond to Tai, who is still on Patch as far as we know. Even if she doesn't get the relic, escaping to Patch without opening the door will at least guarantee the relic is kept out of Salem's hands as long as Raven is alive. And since Cinder doesn't know who she's got bonds to, Raven can be halfway around the world and long gone before Cinder even gets out of Haven.