Then what about the wave of death [1] that happens to people? The body can still release pent up energy well after brain death, but it doesn't necessarily mean the person can be brought back to life.
The wave described in this article is actually atypical brain activity. This confirm that the brain is unstable and the person may be facing his last minutes. This actually make the EEG more precise.
[1] http://news.discovery.com/human/near-death-brain.html