I ran into the same problem last May with them P2 cards. Upon downloading into an external drive, it created folders and thumbnails of the clips. Our 2nd AC was not checking the file size (nor the footage at all) that when it finally came to viewing the dailies, there was no footage at all! And the P2 cards had been recorded over.
I’m still stuck with my original problem. Some clips are not transferring over onto the Add to Queue section. I can watch the clips but can’t edit them.