Yes, I fully acknowledge that Pilate knew Jesus was innocent, yet tried to release him many times. But he didn't release him—He delivered him up to be crucified. Pilate was a weak ruler who would rather do the politically convenient thing and deliver an innocent man to be murdered than do the right thing and protect Jesus from his enemies. Neither Pilate's declaration of his own innocence nor the Jews' assumption of guilt can change the reality that Jesus suffered under Pontius Pilate.
As for the Creed itself, while Pontius Pilate is the only listed, there's no indication that he was the only party involved. Why is he the only one listed? I don't know, and if I were the one writing the Creed I would have included others in addition to him, but even if the Creed isn't how I would have written it, it's still not factually incorrect, nor do I consider it to be misleading, much less misinforming.