Characters: unnamed witches, wizards and Muggles
When the children at Hogwarts were taught about the Flame-Freezing charm, in History of Magic, there were certain details that were kept from them. The Muggle authorities that led the witch-burnings were not stupid enough not to notice that their convicted witch was not dying.
Sometimes, it was decided that the accused must be innocent after all, and under the protection of God, and they were freed, and sometimes even canonised.
More often, though, those who had originally sentenced the accused to death declared their unexpected survival further evidence of Satan's hand.
Burning is not the only way to die.