This is how people can get into trouble with paper wallets - they think of it as an account with a balance. You have to deal with the change or bad things happen.
thanks for the detailed write up, can i ask for an example of what you mean by this last statement? my friend keeps all his btc in paper wallets and spends exclusively from that. i told him it'd be better to keep a paper wallet just for long term storage and use and encrypted wallet with backups on his pc or just open a blockchain account and backup from there, but i couldn't give him a good example of why he shouldn't spend from paper wallets like they are bank accounts....