However this brings to thought, two pertinent questions
- Is there any extrinsic reward if the miner refunds the BTC?
- Is there a punishment for the miner whether big or small if they refuse to make a refund even after it has been verified?
No, there is not an extrinsic reward for that, maybe only Advertising.
Second questions is debatable, in theory there is not punishment, maybe just a little of bad reputation but it wasn't their fault in first place