Did you just say it's their right! Such right, Is it ideal? What's the ethical or moral philosophy behind that right in keeping what doesn't count as yours.
Yes i said so, it is their right to return an overpayment or not, it is their reward in fees and surely it is their right to do what they want with it. Take note that whatever fee attached to a mined tx now belongs to the miner, it counts as theirs and no longer belongs to whomever made the tx. It is just like saying you overpaid when sending BTC's to someone, and now you want some of the output back, it is the goodwill of the recipient to either keep the money or send them back to you, it isn't in the rights of the sender to enforce that refund.
We understand that clarity about tx fees for miners but when you receive what's above your pay cheque especially to that range of amount of tx fees it will be reputable to return it to the owner as it could be an act of error, and no one is above error.
How can miners verify it was a mistake, anybody can come out and claim a mistake. Take note that there is no exact "paycheque" for miners, just take a look at some ordinals tx's and the fees attached to them, whatever tx fee attached to a tx will be taken by the miner as what you wish to pay. True that no one is above mistake, but it is better to let people know the truth so they can double or triple check next time they are about to hit that broadcast button.