Cyberduck just like all other FTP software removes the files immediately, theres no recovering, its not like a the files go to a recycle bin.
All though by technical means, the files arn't really gone, they don't show up and will be overwritten with time. So with some special software you may be able to recover them. As for what software, I don't know.... on the Mac Platform, I was/used to be a PC repair technician. Although you would need direct access to the drive in question...