No, this was fantastic. I even made a thread about it saying how WWE should just turn him or not turn him, but if they don't plan on doing anything with him, they should stop teasing it.
On any other night, this wouldn't have gotten the desired reaction. When a guy turns heel, the reaction should be what we saw last night, but more often than not, because of the writing, it ends up being like it was at SummerSlam with Becky. This was perfect in every way. Roman announces he has cancer, Ambrose and Rollins decide to focus their energy on winning the tag titles for him. Then they do, and you think we're getting a feel good moment to send everyone home happy. But then Dean beats the shyt out of Seth and people are actually shocked and disgusted. It couldn't have turned out any better.
Now we have two feuds with two clearly defined faces and two clearly defined heels. The fact that no one would have expected Dean to do it last night was what made it fantastic. They had telegraphed it way too much lately, so why not do it when no one sees it coming?