User blog comment:IamJakuhoRaikoben/Chapter 450: Alone in all the World, Review./@comment-24.200.220.241-20150831051229/@comment-9595671-20150831154315

I wouldn't be surprised if when he was made the next master, he was told about this. I wouldn't be surprised if Precht felt it the only way he could fully understand.

That and he felt it was the only way he wouldn't blame Mavis, telling him this probably allowed him to explain why it was just an accident and Mavis never intended to take his mother away from him.

Although while I agree it's likely not her sin, that might not change that Mavis feels it is. There are people who may blame themselves over something, even when everyone else doesn't.