GH4 video broken

I have some video that was shot on a GH4 which seems to have been corrupted. It was an hour long interview shot as a 24fps, 100mbps .mov. The camera was stationary for the entire interview, and at no time did it loose power. The camera never registered an error during shooting, and the recording was ended by pressing the record button. After shooting my producer was able to transfer the footage which consisted of several 4.27GB files which all look like this image:

gh4brokenvideo.jpg

We had a lav for audio, but the video has nothing but static.

We were using a 64GB PNY UHS3 card. Now when I put the card in a computer it asks me to format it. When I put it in a GH4 it tells me there is a card error.

I know I'm probably not going to be able to salvage the video, but if anybody has an idea of what caused this, or how it could be avoided in the future I would appreciate your insight.

Thanks,
Dave

Hi Duke, thanks for the response.

Yeah, I've pulled that card out of rotation because it's the weakest link in the chain as far as I can tell. I haven't been able to reproduce the issue with the camera. I guess I just move on and shoot more test footage before each production.