I don't think so. Any projectile of decent mass will be deadly when accelerated to high speed. There's nothing that magically exempts potatoes from this just because they're edible. You can absolutely kill someone with a potato gun. The prosecution in question may be wrong for other reasons (e.g. fired safely and not with any intent to harm), but "potatoes can't kill, because otherwise Ireland would be a superpower" is not the way to argue it.
A comment was made about a lawyer making an argument which, in my opinion, is a bad argument. I pointed that out. I'm not being "pedantic" nor am I "nitpicking" when I point out that a potato cannon is, in fact, a deadly weapon and the lawyer's argument against it is stupid.
Now, I agree that the comment, and therefore the whole thread that followed it, was not really on-topic. But I'm not seeing this whole "pedantic and nitpicky" thing.
