It felt like he was trying not to say anything too derogatory about S3, but its pretty clear he didn't like Cutter's ending any more than we did - he'd rather have gone through an anomaly or been eaten by a dinosaur (think that was on GMTV interview)
Yeah, I thought he was more snappy than in the other interviews. Particularly the lined where the moderator asks him about if the others miss him. He sounds upstage. He makes it very clear that he knows that is was/is his show (the moderator was SO right- it's good that someone tells Dougie that sometimes)
and I did wonder if he was entirely joking about Adrian not liking him too much anymore because he chose to leave!
I wondered that too. I'm sure there's more to it than Dougie wants to admit. It's somehow weird how he speaks about that he doesn't want the show to be too successful.
He's also made it very clear that he gave them plenty of notice that he was going (at the end of S2, I believe) which means there was no excuse for not tying up so many of the ongoing storylines and giving the character a more fitting ending...... 
The problem is that Adrian thought that Cutter's death was done "in a beautiful way" but most people obviously don't agree with him. I don't understand why they cared so less about the character who carried the show from the beginning.
Dougie said that they made Helen shot Cutter because they wanted that there was no way back. Problem is that they already hinted in 2.07 that Helen would bring back Stephen. They should stop giving the fans hope when there is no.