Can the Mavs renege?

This is probably just wishful thinking.  Is there any chance the front office says, "Thank you, Devean, we really dodged a bullet there.  We can now keep Harris, Diop's interior help, our draft picks, and avoid another half season of roster tinkering! " Instead, I imagine they're scrambling to find a way to make the trade work.  Team chemistry is on the line and Kidd is not the best at helping chemistry.  Are the Mavs definitely past the point of no return?