This is yet another classic case of "not dead yet" syndrome. Taken from the book of Python, "not dead yet" is derived from the final words of a man who is nearly dead and about to be taken away. And though these new cases of "not dead yet" may not shout it from the rooftops, they sure as hell do get the point across with their energetic bodily twitches.
Take for instance another case. June Burchell of Sussex was pronounced dead three times, waking up twice in the morgue. Trust me, waking up in a morgue is in no way the same as coming to from a blackout after a night of binge drinking. That is, unless you blackout in a morgue.
Thankfully, advancements in research are being made to treat "not dead yet" syndrome. A scientist by the name of Miracle Max is working on a pill that he feels may cure people who he refers to as "mostly dead".
Let us hope this will be the end of freaking people out at funerals. Only time will tell...