And if they make a stink, they could find themselves facing a lawsuit brought by the fraternity. The Greek system is big business and tarnishing the brand could bring grief down on them.
If you’re looking for another “bad guy” in this scenario- it would be SAE National. They cut these kids off in a split second. So much for brotherhood.
You said it yourself; the Greek system is big business. And no business, regardless of the industry, wants bad publicity smearing it's good name. And this was about as bad as publicity gets, so I'm not surprised that SAE dropped the hammer like it did or as fast as it did. What, after all, was there to investigate and what possible mitigating circumstances were there to what they were doing?