Not so in my experience with AA staff in HNL.
My partner went to return the hire car, so I said I will go check in her bag with mine, forgetting one bag additional free is OWS and above only, so US$200 later that was paid and checked in.
Explaining this to my partner while she was on her way back form the rental drop off, she managed to get hold of someone and explaining the situation, they said they would go and check if the bags had been loaded , and if they hadn't could bring one up, cancel the check in and check it in under her name.
After about 15-20 mins the gentleman returned with one of the bags, cancelled the check in and rechecked the bag in her name and on the spot organised the refund of the US$200 back onto the card I had paid with.