It hasn’t been explicitly stated, however there could have been parts of her neck muscle still attached. Not sure how long it would take for thick muscle to decompose, but certainly there may have been some muscle left when she was found. I found a case in the Spokane area where a cranium was found and the person may have been deceased for a couple of years. In the photo of the base of the skull, there was still muscle and nerve endings attached to where the brain was. It could be similar. I don’t think Cossey has been mentioned yet!