It seems one of the lawyers has written a "combative" letter. (What other kind do lawyers write?) The letter is part of an attempt to keep the paper from gaining public access to notes, emails, etc. regarding the negotiations. (If talks are ongoing, a little privacy might be helpful?)
Legal and PR wrangles aside, it seems to me that the only possible solution will be to add some sort of solar screen or bris soleil to the western face of Museum Tower to reflect sunlight away from the Nasher... and incidentally save condo owners fortunes in air conditioning bills.
I'm amazed there wasn't some solar protection on the tower from the beginning anyway, but since there isn't it can be designed to focus sunlight elsewhere.
A bris soleil on the Times building - image from architechnophilia illustrating an interesting article on architecture and unintended consequences
The catch to this solution, obviously, is that someone has to pay for it. Luckily, the condo owners will be rich people.
This situation is not very different from when any new building diverts rainwater to flood a neighbor: what wasn't a problem before, suddenly IS because of the new construction. The law is clear on the responsibility for site drainage, intruding trees, or wandering cattle - ancient legal squabbles- but not so clear on reflected sunlight - there having been little reflective glass in antiquity, I suppose. But there have been modern precedents, like Frank Gehry's Disney concert hall in L.A., whose reflective skin cooked neighboring condos. I'm sure there are others.
But whatever the legal responsibility or cost, Museum Tower - which takes its name and importance from its location in Dallas' Arts District - needs to be a good neighbor. I think they are trying to fix the problem graciously... Just my opinion, but I think gracious is the way to go.
Not like the Nasher could erect a forty-story spite-fence, is it?