The ejaculation thing is only when they've strangled to death as opposed to having the necks broken.

Maybe it isn't in ALL cases then, but it is definately documented to happen.

Centuries ago, sometimes the gallows where rigged by people who really hated the person about to be killed, so that the trapdoors wouldn't open properly so they would strangle and die slowly, and one of the times I heard the ejaculation thing mentioned was when on the subject of what I was just talking about then.

But I don't know from personal experience