Moving this from the edit to here as the conversation has moved forwards:
While I'm on the subject, it was long ago noted that "Amnesia does not work like that" and so even something turning us from some hypothetical preexistent girl into a blank slate still requires magic to do so, given that that's not how mundane amnesia works.
And reading into any intentions behind that has to jive with the fact that we had very specific set of knowledge that left us obviously equipped to become a magical girl with knowledge of what we were getting into.
(Also, on a tangential note I think it's interesting that while the thread didn't, Sabrina herself had a choice. She could well have let Madoka or Sayaka make a contract to heal her, and they likely would have had she not stopped them. Sadly not something we can say straight for a while yet, but I think it's interesting just how much choice Sabrina's creator gave her, and even power over Madoka herself, in those first few moments.)
We are talking about magic. The mundane equivalent to Vebyast's example would probably be something like "If someone tampers with the fuel in the gas station, and after you fill up there your car breaks down, wouldn't you say that that was caused by the fuel tampering?"