I don't think that this additional ask was in itself the deal killer. I am led to believe that what cemented things was the email from Dubas to Shanahan. My understanding was that this really signified to all on the MLSE side just how badly things had deteriorated between the two that they couldn't meet and finalize terms or talk things out, and instead, it had to be done either through an intermediary (which was Dubas's right) or via email.
Ultimately, the perception was that the relationship was irreparably damaged. am not of the belief that anyone is blaming one side, but that those who were advising were of the belief that it was "too far gone'. Rest assured, I have been told that the board has full faith in Shanahan, so you can read into that what we will.