

Well that’s the trick, isn’t it? The people who rule presume consent, but what they are really expecting is compliance. Your compliance is presumed consent. You can revoke your compliance any time you like, but the rulers will respond to noncompliance with force.
If he talked to you about it, you probably would have talked him out of it. Tells me deep down he knew it was stupid, but he wanted to do it.
I would talk to him about that part of it, help him recognize the choice he made to ignore your voice of reason in his own head.
I wouldn’t punish him for it, especially because he came to you to talk about it, but he’s getting closer to the age when he has to really pay attention to that voice in his head because you won’t be with him for every decision. Although, my kids often act like having to talk to me about things is punishment enough.