It seems that Chris Butcher wasn’t just right, he was prescient. In a recent back-and-forth with a manga publisher, he pointed out that:
“This disclaimer you print in your books, that ‘All characters depicted in sexually explicit scenes in this publication are at least the age of consent or older,’ isn’t worth the paper it’s written on, and is assuredly going to be for naught in front of a judge or jury (you should ask your lawyers about that, while you’re talking to them…).”
Now there’s this thread at The Engine.