The episode is described as: "The tables are turned when past Beat Bobby Flay judges Christian Petroni and Leah Cohen return to the kitchen to take matters into their own hands. Cooking Channel's Laura Vitale and Chef Jet Tila judge the judges to deliver the verdict on who will serve Bobby justice."
Christian has been a judge on the show before, but this is his first time competing on Beat Bobby Flay. I also don't think this is his "prize" for winning Food Network Star and this was probably filmed a while ago. Appearing on Beat Bobby Flay was Bobby Flay's hope of a consolation prize for Manny.
I will update this post after the episode airs to let you know how Christian did on tonight's episode of Beat Bobby Flay.
UPDATE - Christian beat Leah Cohen in the first round and got to face Bobby Flay. The judges decided that Bobby Flay had the better dish, so Christian Petroni did not "beat Bobby Flay."