OrganEx restored circulation and prompted the repair of damaged cells. For example, the scientists saw heart cells contract and electrical activity return. Other organs, including kidneys, also showed improvements, the study says. 

The pigs treated with OrganEx startled researchers. During experimentation, the dead pigs’ heads and necks moved under their own power. The animals remained under heavy anesthesia. 

[...]

The researchers do view the neck jerk is an indication some muscle function was restored after death. 

NBC News