Finally, there wouldn't be enough soft tissue left on a mummy to determine whether or not it was necrotic. You could possibly suggest an episode of osteomyelitis (bone infection) in a mummy. Osteomyelitis after a fracture is not at all typical (particulary a closed fracture in an otherwise healty individual), and it also doesn't develop and kill you in a day. Either these scientists are weak, or their actual statements have been distorted by the reporters.
Thanks Doc! Great to have a professional opinion here.