It's not a case where the US and EU companies are on the same side like I originally proposed, but those might be too rare to test anyway, so I was probably being a bit silly.
Failing back to these more common cases, I don't think (and shouldn't have implied that) one case alone in a decade completely decides the question of bias, but it should definitely shift the probabilities here, if you want to be bayesian about it.
EDIT for emphasis.
It's a complicated counterexample to the premise that the EU is preoccupied with fining US companies.
We are less likely to hear about small companies getting fined by prominent bodies, because they have less impact, because their case doesn't receive public attention, because they don't lawyer up in long protracted battles, etc.
> the Spanish media vs. American tech firm
One is a press organization, the other is (usually) an ad-tech business. Different rules apply for different deontology sets. Much like FB doesn't get the same slack as the NYT when it comes to disclosing stuff.
> US companies were, collectively, fined slightly less than their share of economic activity in the EU,
I can imagine why you would control for economic activity, but I have no idea what impact that had on the results relative to other reasonable controls. If we're wondering about punishing bad decisions, you could have instead controlled for the number of decisionmakers from these companies in the EU. Or you could have controlled for the number of different endeavors or types of products or lines of business (because each different source of revenue is a source of malfeasance moreso than each individual euro earned). I'm really mostly concerned about that last one. What is the chance each revenue stream will get more scrutiny by being foreign? Court cases don't target individual euros earned, they target a certain product or way of doing business.
Regardless of controls, it doesn't change the tortured logic in some high profile cases comparing US and EU institutions under the same standard. If the Spanish media publicizes something as widely as it can, that's great, because it's good for the public to have that information. If an American tech firm allows people to access those publications, that's bad, because it's bad for the public to have that information.
I'd love to change my mind about the bias in the EU, I'm open to new evidence. All it would take is a few EU cases where they found that the big American company was blameless, but the small European company should be fined.