Iodine requires a client and a server. Both belong to you, what is the problem here? That I use a network to transmit packets? We are not talking about installing iodine on someone else's computer!
"My son handles the computer stuff for me, I don't even know about that logging page you're talking about."
"I thought restricted networks had a WPA-2 password? That's what they use at my workplace."
Judges just aren't that stupid.
Who can tell me with a straight face that this is criminal behaviour
Maybe I'm not understanding this correctly, but if a coffee shop has wifi and you need to enter info into a captive portal before you can use their network, by circumventing it, the "Someone else" is the coffee shop owner, and the hardware is their router.
"Please get off my router if you don't agree to my conditions". "Nah I'm just using DNS, it's fine" probably is not an admissible excuse.
If the shop don't intend the use its not authorised. Your ethical framework may not put any value on that lack of authorisation, but you see the action is unauthorised, surely?