What constitutes "life in prison"?

Benjamin Schreiber was sentenced to life in prison without parole for beating a man to death back in 1996. In 2015 Schreiber had a medical emergency from a kidney stone where he died on the operating table & was brought back to life. Schreiber is now claiming that he should be released from prison because he served his life sentence by temporarily dying. Actually, he was revived 5 times. The courts are refusing to release him from jail.

Since this is a new twist as to what constitutes a life sentence, I’d like to hear your thoughts on this subject.