A dead body found to have cadaveric spasm after strychnine poisoning. Which one of the following is TRUE regarding cadaveric spasm?

Cadaveric spasm or Instantaneous rigor or Cataleptic rigidity: In this, the muscles that were contracted during life become stiff and rigid immediately after death without passing into the stage of primary relaxation. This is usually limited to a single group of voluntary muscles and frequently involves the hands. It occurs especially in cases : Sudden death Excitement Fear Severe pain Exhaustion Cerebral hemorrhage Injury to the nervous system Firearm wound of the head Convulsant poisons such as strychnine It passes without interruption into normal rigor mois and disappears when rigor disappears. Ref: The Essentials of Forensic Medicine and Toxicology by Dr K. S.Narayan Reddy, 27th edition, Page 143.