I think this will get done with a 2nd round pick, so that CLE can save face.  Doubt Ainge would offer anything else.
Also wonder if both sides could agree to let Silver decide what should happen, after presenting the facts. 
There is no way a 2nd round pick saves this deal.  You can buy 2nd round picks every draft.
Cleveland examined IT and determined that he needs surgery.  He will miss most if not all of the season.  This dramatically changes their value in the trade.  It is that simple.  
They should rescind the trade. 
Yeah, I'm still calling BS on this.
I still think they're exaggerating their "different interpretation" to try and get more out of Boston, which is evidenced by what they're asking for in addition to the package. While IT certainly could be worse than they thought, I do not think the difference in interpretation is as sizable as their asking price is suggesting.
Otherwise, this is purely a failure of comprehension on Cleveland's part. By all accounts Danny was more than forthcoming regarding IT's injury, so the fact that Cleveland underestimated his injury and overplayed their hand shouldn't necessarily be grounds for reneging on the contract. That's the only explanation that makes sense, because no reasonable person thinks Kyrie equals that package without there being risk with IT's injury, which is evidenced by most of the media calling this a major overpay as soon as it happened.