I wonder what the thought process (or perhaps lack thereof) at Apple was. Did no one of the likely-somewhat-large team who did that think "wait, this could lock out our users who may have used that character"?
In the immortal words of Linus Torvalds: "WE DO NOT BREAK USERSPACE!"
Now one of the ways in might be those companies who claim to be able to break iPhone security for law enforcement and the like, but I'm not sure if they'd be willing to do it (at any price) unless you could somehow trick them into thinking you had some "interesting" data on there...