Well, it wasn’t so much “bad clips” as clips from a previous shooting that nobody had bothered to delete, so they would have been duplicated. And yeah, disk space is cheap… but it adds up (specially because it isn’t the first time people don’t bother formatting a card before starting to shoot). The error, of course, was in trying to delete them in-camera, instead of on the computer, once they were safely copied.
As for the cards, I called two different companies, and they both told me that the only hope was to send it to Panasonic’s factory, either in Germany or Japan, where they have special equipment originally developed to save footage from defective cards, that it could take up to six months, and that there were no guarantees. I did try on my own with Data Rescue too, but all it could save were two thumbnails from two clips.
So, moral of the story? Go back to Umatic tapes, guys; this whole non-linear, “tapeless workflow” thing is a scam… 🙂