No, I do not think that the Big Basin (BB) photos were conclusively discovered to be faked by those details. I'm not saying that they are not faked though.
The 12 BB photos arrived to Linda Moulton-Howe in printed format in an envelope, and she scanned them into her computer (which I think was a Mac) probably using an Adobe product to save the scanned files.
The squares seen around the arms are a common JPG compression artefact that will occur with any photo compressed to a small file size.
A side issue is that she scanned the photos at a low resolution and would not release the higher resolution images to the public because she thought that would be a way to prove who the original anonymous submitter was later, she just ended up making her loyal followers angry that she would not participate in the research.
