Criminal negligence doesn't require intent. If you fire your gun into the air because you are a jackass, and the bullet comes down somewhere and kills someone, the gun is still a weapon, even though you had no intent to kill.

I think he meant the intent of the creator of the compound/item.

A gun is created to kill. A taser to incapacitate. A knife is created to cut/stab things - and since human flesh is highly cuttable substance even kitchen knives are considered weapons. A car is created to transport people but can be used to kill. Cars are not weapons because in their conception there is no intent to harm someone.

What about a rock? The same analogy holds true. Anything can be a weapon, its simply absurd to contend that intent matters.

There has to be intent in there someone. A gun is a weapon. A rock can be a weapon. A dangerous polluting factory may be criminally negligent and morally despicable, but it's not a weapon unless it was deliberately deployed to maximize exposure to a target group. (Which isn't out of the question, given human nature, but I haven't heard of any evidence for it happening yet.)

What if we replace the gun and bullet with a bottle rocket? Is it a weapon now?