User blog comment:Lillybopeep/I get it know!/@comment-28293237-20160619130438

I agree that saying Voldemort killed Cedric was not a mistake by Jo. But I think the main reason why is this: Dumbledore and Harry had no concrete proof that either Voldemort or Peter were still alive. A big thing over the next year was how everyone was doubting their claims about Voldemort. It was crazy that they were accusing one person everyone thought was dead was actually not, but to bring Peter into it too?

Peter killed Cedric on Voldemort's orders so they were both responsible, but Cedric was also killed with Voldemort's wand. Dumbledore focused on Voldemort because he was a bigger threat to the Wizarding World. If they could convince and prove Voldemort's back, they would have had a better chance of proving Peter was still alive.

So to prove Peter was still alive and a Death Eater, they had to prove Voldemort was still alive. If they suddenly started saying Peter was alive with no proof and that Sirius was innocent, they would be putting Sirius in danger. Suddenly Dumbledore and Harry have become Sirius sympathizers. The Ministry will think that they know where Sirius is. They will think they have either been hiding Sirius willingly or that Sirius was making them say these things. Either way, the Ministry would have tried to use them to get to Sirius and if they found him, not only would the Ministry arrest them for hiding him, they would also arrest and then send Sirius to the Dementors.

So saying Peter is alive as well as Voldemort would have made them look more ridiculous in the eyes of everyone else and it would have brought up far too many questions. Dumbledore wants and needs everyone to worry about Voldemort at that moment. Not Peter and Sirius. Without proof Peter was still alive, there was no way to prove Sirius innocent anyway. So, make everyone worry about Voldemort. Find proof Voldemort is still alive. Prove it so everyone takes them seriously. Then deal with Peter.