Why did the mother's husband and son have to be killed to make a profit?
Lady Snowblood's mother claimed that the four killed her husband and child for profit, yet their plan to scam the villagers for money could be executed without the murders.
Not sure if this confusion comes from the subtitles (I watched the Arrow Video Blu-ray) or what. Could it be that they knew he was a teacher and thus because of his knowledge could be able to expose their charlatanism?