It doesn't really matter if they are a little dissimilar. I got confirmation saying that they were very similar. They are both cuts across the entire front of the neck. That is not something that needs to be super analyzed.
And while you're saying it's unlikely, it's still very possible and not valid evidence.
Oh, excuse me, I'm sorry for agreeing with the truth because there's a ridiculously unlikely alternative.
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Black Turtle did a pretty good job.