I haven't read through all the comments, but I thank anyone giving the benefit of the doubt to the owners and dogs. I've flown with my service dog 11 times, and let me tell you, he still absolutely hates it! He's as close to bombproof as it gets everywhere else, but something about the altitude changing sends him into hysterics. I'm not taking about something disruptive, but clear signs that he's in distress (stress panting, stress drooling, sometimes whimpering, shaking all over). While doesn't seem very "service dog" at all when the trained eye sees him. In the airport after we get off the plane he is almost always frantic and wants to approach and greet everyone in the waiting area (which I don't allow, but he tries hard!) honestly flying with him is so nerve racking, especially considering he's my PSD and is unable to help much when he's stressed out like that. It's unfortunate, but I can't travel without him or I'd be without him at my destination.
We're a perfectly legitimate team but that is his cyptonite.
There is also the perspective that it could be ESAs the OP encountered, which almost always behave like little shits because they aren't often held to the same standard a service dog handler holds their dog to. It's also possible they were faking to fly their dog for free which is also common, but I've seen equally as disruptive ESAs as I have assumed fakers.