Bitter Blame
The sorcerer was bitter, and with good reason, having lost his wife and child. The culprit had been time, not fate, which seems to suffer from whims and prophesies and a peculiar sense of duty. Time simply carries on, tearing down along its way, strangely making everything more beautiful.
It will come as no surprise that the sorcerer cast blame where it could not possibly be affixed. Witches have a way of getting into the middle of this sort of blame. It's not a talent; more of an occupational hazard. This witch had been the one to tend the boy and his mother.
There would have been a spell. A complicated, carefully crafted one, designed to torment its victim until the end of her days. And yet, the witch did not hide in that way some do - the ones that have a tendency to fail escaping the notice of those with a tendency to tyrannous practices. She stepped into the forefront of his grief, for no other reason than that he might not be alone.
Thus, the blame passed into nothingness.
There it doesn't lie, not existing.