Revisionist history from a Mittbot. How surprising...
For what it's worth: the smartest, most well-connected old-school newspaperman in Washington was Robert Novak, and he had reason to believe that Mitt Romney's people were, at the time purposely trying to create a wedge between Mr. Thompson and John McCain.
He published his thoughts on the matter in his column of 1/5/08, and having read his work for over 30 years, I inferred between the lines that he had a good source informing his suspicion. He almost always did.