If you have your wallet backed up, you can just restore your backup wallet.dat. Since the last transaction is not verified, your bitcoins will not be spent.
If you enter a broken address, there is a good chance that the transaction will not happen in the first place (because of the checksum). I think he's talking about cases where a transaction goes out, in which case it will surely get confirmed.
I actually did send bitcoins (with no fee) to another wallet on a smartphone, but while the trasaction cleared the bitcoins from my pc wallet, it did not appear on my smartphone even after several minutes. I then recovered a backup and sent the same bitcoins to another address (MtGox) this time with a fee and they did move to MtGox. I suppose I double-spent them, but it worked.