That's actually quite interesting from the legal point of view. As much as it's not something that would be reportable to police, depending on the jurisdiction, you could still take the miner to the civil court with a chance of winning.
I bet 99.9999999% if not 100% of lawyers and judges have absolutely no idea about how bitcoin mining and blockchain network works. This would be the case where they'll have to judge what they don't know and won't be able to understand which argument is right or wrong.
We aren't students of school of law but we can logically say that there is absolutely zero chance that miner is guilty. It's miners duty to mine bitcoin block and keep mining fees. I would even say that if miner agrees to return fees to someone, they are probably part of money laundering. Why? Because, why would someone pay half a billion in fees and then ask miner for return? To launder money, that's how they do that. We can argue on this, right? Sure. But the best judge in this case is Bitcoin Whitepaper, it doesn't say that we should return fees to transaction makers. Instead, miners should keep them, it's their property.
Despite the majority voting against it, apparently they did the right thing and returned that fee anyway:
Who's to say it was the right thing to do? Whenever the average user makes a mistake and over pays their fee, they simply have to wave goodbye to their money. Why should it be different for Paxos?
Average people getting screwed while corporations do what they like is all too reminiscent of fiat.
The most interesting part is, what would happen if they didn't return fee? What would PayPal and Paxos do? Would this motivate them to immediately start demarketing of Bitcoin and decentralized Proof Of Work? Probably it was a right choice this time because these big corporations have enormous power, it would make F2Pool and others to look bad and PayPal would try to market itself even better and socially step up because as you know, people are naive and lack critical thinking. Otherwise, I totally agree with you, big corporations should pay! Always!