I switched over and caught a few minutes of this today(well yesterday now) and he was talking about Ben10 movie. I don't know if he maybe just isn't much good without a script but he didn't sound as bad on the film clips as when he was bing interviewed. he was very slurry and quite rambling.
I watched this interview at the time and thought quite the opposite. I don't know where you get the slurred speech or rambling from but it certainly wasn't him. I remember Fern and Eamon asking pretty infantile questions and not being well briefed, so probably like me, Lee was just bored by them and waiting for the interview to end. Lee was pretty tolerant given the level of questions he had to answer.