If a card holder is deceased but a family member had an additional card and charged over 5K since the death is this considered fraud and does the estate have to pay the debt?

Yes, it IS fraud, and the estate should NOT pay the debt, instead the trustee should turn in the criminal to the credit card company and point out that the estate of the deceased is not responsible for any debt incured after the death date. This would be fraud. I am sorry for your loss, and all of the trouble that you and your family are going through now. God Bless:)