Triple H has only been a face in NXT. He's always been portrayed as a heel on WWE TV since turning on Bryan at Summerslam 2013. There's been times where he's shown Seth "tough love", but he's always been the face.
Triple H promised Seth the world to break up The Shield, he constantly tried messing with Ambrose and Reigns since the split, his (HHH's) golden child of The Authority screwed him out of his Wrestlemania main event and the same thing happened at Survivor Series. Very easily, this is a long time building and Reigns can no longer hide behind a fake smile he's shown every night. He finally snapped.
Barrett didn't come out either. Say Barrett attacked Ambrose backstage and set them up for a Rumble match, or even better, find/show some footage of Triple H and the League of Nations beating down Ambrose backstage to make sure he wouldn't be able to get involved in the main event.
But he wasn't directly involved in any of those events (and some of those are so old it doesn't matter anymore. It is wrestling, year and a half burns don't usually happen).
Seth broke the SHIELD up, Seth cashed in on him. Seth was champ. HHH offered him the title after Seth got hurt, he said no.
Roman won anyway, HHH went to shake his hand and he speared him and sheamus cashed in.
That's the problem. HHH is some guy behind the scenes, but he hasn't directly ****ed Roman over. If he came out and helped cost him the belt tonight, it would of made more sense. It just feels really forced, and maybe its just because there is no one available so they can't do the feud with Seth that needs to be done.
They have to address where Dean was though or that is awful storytelling. I think it would of been better to have their relationship fall apart over this, but it doesn't seem that is the plan.