To transfer Nikon D5100/D800 MOV files for editing in FCP, you can get the Nikon Video Converter for FCP 7/FCP X to convert Nikon .mov with H.264 codec to FCP ProRes.
Transfer/Backup MOV files from Nikon D7000/D3200/D5100/D800 to Mac, Macbook for importing or editing Nikon MOV in iMovie or FCP, after converting Nikon MOV on Mountain Lion, Snow Leopard, etc.