Surely omitting some emails is different from omitting pieces of some of the emails to change the meaning.
I don't understand your example - murder coerced by blackmail is still murder. I imagine if this email was actually released to the public and people found out I was a murderer, when the police arrived I would show any documentation of the threat or call attention to the fact that my missing relative was being held. Society would be better off knowing I was a murderer and that I claimed to be coerced because then the perpetrators would at least have a harder time reusing the same tactic.
If that murder evidence email was released and discussed online, it'd be weird to see it be disqualified in discussion, despite being believed to be true, because of a belief that there might be a second email which compelled the execution of the murder. It would be fine for someone to show this second email as part of a defense, but again this example is kind of tricky because being compelled to murder under the threat of murder doesn't justify murder.
- cmdrfred
Technically you wrote those words in that order, but by omitting other words the context was completely lost. This is why selective omission is dangerous. s/word/email/ and you have the Wikileaks situation of omitting certain emails. This is why, when people take the stand, they are asked to tell the whole truth. Because when you omit things, you lose the context and change the situation.