From everything I have read and heard about this case I honestly wonder if their plan did actually go wrong or if what happened was what they (or especially he) intended.
Apparently some of their neighbours were soot covered and in need of medical attention after trying to rescue the children, but Philpott was completely spotless. As a PP has said, he didn't want to go in the ambulance with their eldest and had to be persuaded to by the police. At the mortuary, Philpott flirted with a female police officer and referred to his kids as "little sh*ts". Also as a PP has pointed out, they were having food fights in the hospital canteen and went out to karaoke within days of their children's deaths. Hardly the behaviour of grieving parents.
I did also watch the Panorama programme and was just disgusted. Philpott was the one who asked for the press conference, but neither of them shed a single tear, even though they kept covering their faces and dabbing their eyes. The look on the face of the Police Inspector, who was sitting next to them, said it all.
A truly horrible, despicable pair. The jail sentences they both got were a complete joke.