Cycocelica,
Although the knowledge base article above may describe Apple's written policy, IMO it's more of a scare tactic and not their actual practice. Apple knows that not everyone is going to backup after every song they download, so they generously provide an "exception."
I personally feel that Apple owes its customers that service (much like Napster and Real Rhapsody already provide), but to each their own.
Here is the link I mentioned above.
http://www.apple.com/support/itunes/musicstore/lostmusic/
Next time, be sure to backup your data.
😉