Oh, neither I nor kstu said it was. You're simply a complete idiot for not understanding (or pretending to not understand) the difference between somebody who is one day away from being 18 and somebody who IS 18.
For all intents and purposes, there is no difference. Only legally, and I'd be willing to put money on the DA not being able to prove beyond a reasonable doubt that the girl was 17yr364d old if it actually went to court.
Well yes there is something to that, but the issue isn't only over a day, there has to be a threshold to hold people accountable for their actions and in the UK that is 18, both in law and as a social convention, I see no issues with that, I'll grant you if were arguing over days then to most people it wont matter, but none the less you start arguing days, then weeks, then it's well she was nearly 17 so it was ok. It's a slippery slope, though it may seem strange to argue over a day or two, it just makes logical sense to say this is the line before is not ok after is, to avoid confusion.