I would say the person doing the crime himself is to blame for his own death. I think there’s a difference between an accomplice and an innocent dying.

But its a fine line, I agree, and also depends on other variables. If I start applying it to other examples:

If you are trespassing in a train tunnel doing graffiti, the train comes and you get out but your buddy gets hit, is it murder? I’d say not really.

If you’re racing and your buddy hits a tree, it’s not really murder either yet he wouldn’t of been racing alone. It’s a two player sport so I’d tend to say guilty.

Would your buddy have stayed home instead of robbing the store if you weren’t there to help him, it’s hard to say but I’d tend to go not guilty.

It also seems a bit vindictive but like I said, I understand the sentiment.

The hard part is that “direct” is subjective and up to interpretation of the court.

Oh, agreed. Should have a way to punish someone for trying (e.g. attempted murder charges because the police stopped the murder and saved the intended victim). But even then, one still has to be able to prove it, and the level of proof - beyond a reasonable doubt - is as high as it is for good reason.

Now, if the accused had encountered police detectives at that polling station instead of real election workers, I imagine it would have gone like this:

(Police detective posing as a poll worker prepares an otherwise blank but non-obviously spoiled ballot.)

“Ok sir, here’s your ballot.”

Choice A: “Thanks, here’s the ballot, yay I just voted.” “Sir, you’re under arrest.”

Choice B: “Um… actually I already voted.” “Yes we know sir, I see it right here, but we were just testing you.” “No, hey, wait, I was trying to test you.” “…”

It’s not a reasonable expectation to ask actual election workers - poll working volunteers - to do anything like the above, though.