Some people when joking aren't really joking and are trying to pull the old "If you say yes I was serious, if no I was joking" bit. It's annoying and the same as asking for OP which is why we don't allow it (I haven't read the original remarks so I have no idea what this case falls under). It's up to the mods/admins to use their judgement as to what crosses the line or not.

If someone is banned and you legitimately feel it was unfair (not just a "mum said no so I'll go ask dad" situation) and feel like there should be another opinion then make a ban appeal (before the ban expires) or send another admin a PM here and we'll check it out. I check the site daily and I imagine the rest of the admins do too so it shouldn't take too long for us to see it and look into things (obviously note that we are all in different time zones and have work/school/something that resembles a life, so can't guarantee an instant reply).

Top's right that the general rule has been around for ages but for the future and for clarity I've added the "joking/not joking" part to the rules page.