What happens if a check card authorization has been canceled by your bank but you still owe it?

My brother ordered some things online last week (around $100?) and it has already been shipped and is supposed to come today. He had an authorization on his check card for the amount, but today the bank canceled it and made it availible because the merchant never deducted the money from the account. He is all excited saying "I could go take all the cash out of my account and it would just be too bad for the merchant". I told him the merchant will eventually try to deduct the money and it will be an NSF. He said no it wont, it would be like your card getting declined. So I want to know who is right and also who agrees with me that he is shady! Thank you!