I think that the story leaves a lot of uncertainty in its depictions of other characters' disposition towards Harry and each other. We still don't know what level Dumbledore's playing on. Did he notice Harry in the prison cell (he could, since he might have mastered the deadly hallows)? Did he connect the hole in the wall or transfigured rocket fuel with Harry's magic style? Could he stop rocket-powered broomstick in time? Is he Santa Claus? Did he mislead McGonagall to try the flawed test? Did he prompt Snape to confront Quirrell at Mary's Place? What does he know and suspect about Quirrell?

McGonagall seems to be irrationally optimistic about everything and hopeful about Harry. Snape underestimates Harry, or at least doesn' t interfere with him all that much. Mad-Eye doesn't know Harry personally, or else he would probably instantly unravel all of his plots and half of Quirrell's and Dumbledore's for good measure.