Pay back to Trump for all the times he ran him out to lie for him, and then turned around and said something totally contradicting what Spicey reported? Or, perhaps for not letting him see the Pope on their trip to the Vatican?

If the birds are starting to sing, in public, like his lawyers talking in a restaurant, no telling what they're singing when they are with Mueller, in private!

http://www.cnn.com/2017/09/18/politics/ty-cobb-donald-mcgahn-white-house-lawyers-new-york-times/index.html