if the goal is to target Rusty in fact nothing would get out externally it would remain an internal blackmail, a picture of a DIk or Rusty himself taking drugs has some power.
here we are not talking about disciplinary action against a fraternity, which at that point would have good game in revealing how other fraternities also do the same by putting Burke in check
here we are talking about blackmail designed to get something out of the Burgmeisters, what do you want that Rusty's father care that Dawe is also on drugs (with sugar pills)? he only cares that his son's reputation is not tarnished
but let's even assume that this impasse works, if drugs, alcohol and prostitutes are not enough what should Rusty do? rape? murder?
Dude, I'm talking about doing favors for Rusty and his family.
We know that Cathy has connections with Rusty's family, we know that it is Cathy who has supported Rusty and the DIK's, but can you imagine what would happen if Cathy left? On campus, who could support Rusty and the DIK's?
Cathy was furious with what happened, the DIK's were close to destruction, and the only person who could try to protect them is the victim in question, "lucky" the MC managed to appease Cathy, Rusty cried in front of her asking apologies, seeing that, she relented, and then she exonerated the DIK's and closed the matter.
But can you imagine if she didn't forgive the DIK's? Who would speak for them, perhaps at the last moment Burke could step in to help them, thus doing Rusty, or more specifically, Rusty's father and family a favor.
Burke, as an antagonist, could be behind everything, he creates problems behind the scenes, and appears to solve them, earning everyone's gratitude.
Anyway, we know that he is aware of everything that happens on campus, he is no saint, he had to buy his position, do you think he did it just for the title? Do you think he's satisfied with the little power he had to pay for?
And the focus is not on Rusty, but on the entire campus, and we know that Jill Royce gets special treatment, would he bend the rules for her without getting anything in return? He probably did the Royce family a favor, and at some point the Royces are going to have to pay him back for those favors.