That being said, I dont see how any bitcoins were lost given the example in the post. When the wallet from the flash drive was restored, he should have access to the coins again.
That the client is problematic doesn't mean the data/$ is gone.
A. Send them to someone else, which will create a new block in the chain that is confirmed by miners. B. Lose your wallet.dat completely and therefore your private keys forfeiting any way to access BTC that are yours.
A very legitimate way of backup up BTC is to just copy your wallet.dat and blockchain to a thumbdrive and store it in a safe deposit box offsite. If you ever lose your main computer for any reason, restore the backups from the thumb drive, let your blockchain catch up to current, and all your money is still intact.
If you restore your wallet.dat and let it catch up to the current blockchain, you will still have all your money, unless you really spent it.
edit: Ok, I guess I am mistaken - I see now how this happened with a really old version of the client. Newer versions of the client pre-generate several addresses in your wallet.dat, so even if you only restored an old version of wallet.dat, you would still have access to any money that is in the blockchain that you spent in the recent past. Of course, you should never let your wallet.dat fall too far behind.
If you back up your wallet prior to the transaction of 1BTC, it will not receive the private keys to the change address. Your private keys in your wallet.dat will point to an empty account. That is what this entire post about losing $81,000 is about.