Rex Is Not Your Lawyer... and David Tennant's Not Your Voice Coach

One of the first things David Tennant did after leaving Doctor Who was star in a comedy-drama pilot for NBC called Rex Is Not Your Lawyer, playing an American attorney who starts suffering from panic attacks so decides to tutor his clients to represent themselves in court. The pilot wasn't picked up, so the project died. But, thanks to the digital age we live in, someone's kindly posted a clip to YouTube (see above). I guess the question on everyone's lips is: what kind of accent was on Tennant's lips?