Kraft ain't going down that road.. I think brady being exonerated is a victory for them too. Kraft also wants to make sure he gets in hof, although not directly related I'm sure it plays into it.
And it's really tough to go after the league when you own a team. I know its not identical, but it'd be like owning a dunkin donuts franchise, they punish you for something stupid, are you really going to take dunkin to court?