SD Card, Error Code 36 after copying additional files to a camera memory card using finder

I'm getting an Error Code-36 when trying to retrieve files from a FAT32 SD card (from my camera) onto a mac formatted drive. Half of the files will not even open, let alone copy across from the card!

I now think I know what caused this behavior but cannot find the solution to retrieving the data.

Some further detail:

I was going to lend the SD card to a friend which was full of .movs from my camera. I also copied some additional files from my desktop onto the card that they needed. I believe this is what has caused the issue as there is now some confusion over file system types within the SD card.

Does anyone know how I can make a backup of the SD card before reformatting inside the camera?

P.S. the error code 36 is being raised by normal .mov files, NOT a hidden 'dot file', I've not tried a dot-clean or disk repair yet as I'm weary of loosing all the files.

Thanks so much