Subject: How do they get sperm out of a dead man

I have heard that doctors have taken sperm out of a dead man. Does this mean 
when a man dies, he has or by some means can have an erection, and that somehow 
he can still ejaculate when his heart is stopped?

Can a man ejaculate during a trauma?

In the movie fatal attraction, in the beginning of the film, a man is killed 
while having sex. Is it possible for a man to ejaculate shortly after being 
killed as was depicted in this movie

Re: How do they get sperm out of a dead man