The “onebox domains blacklist” setting in the admin panel could be used to disable oneboxing for dailymotion. You’ll need to add “www.dailymotion.com”.
Note that any existing posts with oneboxes will need to be “rebaked” for this to take effect - easiest way to do this is to click the wrench below a post and click “rebuild HTML”
Also, onebox does a lot of caching, so it may take a bit of time for the blacklist to take effect 