I was quite annoyed by how Voldemort's death was portrayed, but I'd say the omission of Pettigrew's death is what bothers me the most (I think it was probably deemed too disturbing to show him being strangled by his own "hand", but the hesitancy he showed in killing Harry when Harry reminded him of how he had saved his (Pettigrew's) life earlier, was maybe not redemption, but it did show to me there was still a shred of something resembling decency in Pettigrew (and I think shows that, while he was a traitor, his actions seemed to be mostly out of cowardice and an unwillingness to stand up to Voldemort rather than truly being a cold-hearted, merciless killer who enjoyed the circumstances he was in.) The movie doesn't give us this.