The problem seems to be that springboard locks up in an endless loop, restarting the device wont help it because its still loading the offending notification from the cache.
Ahhh, I give up. Just try reading what I wrote before replying, mkay?
And in this case Apple's approval process could protect the consumer. They would never let something like this past the gates.
Also, since this issue is very trivial to trigger, it's not very difficult to hide the triggering mechanism in a malicious application in a way that even a reasonably thorough source code inspection would not necessarily spot it. See also: The Underhanded C Contest.