I had a card reader that was doing something similar. One way to tell is by disconnecting and then trying again, if the pictures are still messed up, but in different ways or patterns, then its the card reader, if every picture is the exact same every time, then its the card. I almost trashed a bunch of cards before i thought to try a different reader.
I have had unusual image displays not unlike this if I tried to view images from a new camera on image browser software that was out of date relative to the new camera. Also try the different card reader or different computer as suggested by Dark Reality. It should be pretty simple to isolate a problem CF card if the card is the culprit as Neuro suggests.
Put the card back in the camera and hit preview... if they're all fine, then it's the card reader... You can transfer from the camera via usb cable. If they are corrupt, then as Neuro said, alas it seems like a corrupt or worse faulty memory card. If your friend has a 2nd card, that should eliminate the source. Try reformatting the card, writing some shots and reviewing to eliminate the card. If a 2nd card has the problem, ideally different brand, then sounds like a weird fault on the 1Dx....
Oh and check pins in the slot that none are bent....