Questions like this usually get posted on the message board at my website. I thought I would share my take on this issue. When someone has a conflict in taste, do you upset them and make them pay for the item they did not like, or do you just bite your tongue, apologize and let them order another menu item at your cost. I run across this more than I like to. I don't blink an eye if I think it is not cooked to perfection, but if it is because they just don't like it, or it's not what they expected' and we sell a lot of them without any complaints or even been complemented on the item, find it hard to understand.
Life is too short to waste any time getting irritated, particularly at a paying guest.
If a guest returns an item, don't waste time grilling them about why or looking for logic. If they don't like it, whatever the reason, swallow your ego and replace the item at no charge. It is not worth the mental stress. I will transfer this whole exchange to the message board. If you have any other approaches to offer, please add them on the message board.