There was a time when people waking up in their own coffins or at a funeral was more common. This only became less frequent after embalming became common.
This means that there are people who didn't really die who die from embalming!
Since this is a risk they shouldn't do anything to the body that would result in death if it happens that the body isn't really dead yet. They should watch the body until they can be certain the body is dead and only then do anything with it.
If someone is declared dead by multiple certified doctors, there is no way waiting a while will give them a better chance of living.
"OH God, Jimmy's dead!!!"
"Are you sure?"
"His head is missing..."
"But he could still be alive"
"Let's stick him in the closet for now, we'll check to see if he's okay later..."
*2 weeks later*
"He's still dead..."
"He's a rotting pile of flesh"
Medical science is not exactly at the point where we are burying people alive anymore because they fell into a vegetative coma. We have all manner of instrumentation to ensure that the dead are in fact clinically dead. Doctors calling a time of death must even have a witness present to reaffirm the call.