If Arte wanted to sue to enforce the contract (and he had completely “clean hands” in the deal), then he could try to force the sale per the terms of the contract. Though I don’t know how far along this was, I assume the actual contract had been signed. Then again you also get into real estate transaction law which has its own ins and outs beside that of pure contract law. Generally, again if Arte had clean hands, then he could also find an alternative and sue for the cost difference assuming he attempted to mitigate his damages.
That’s a real basic explanation and I’m not the guy to go beyond that, but my point is that if Arte was completely free of any bad behavior in the deal, knowing that he isn’t one to back away from litigation, then I think he would have sued to enforce the contract, especially if the terms are better than what he thinks he can expect be renegotiating. He didn’t just agree to let Anaheim out of the deal because he’s a nice guy. My money is on that it was a shady deal all around and they don’t want to risk that coming out by litigating. Just my opinion, of course.