I don't think that is a fair comment. I am sure there are some very decent parents who have had their kids turn out to be monsters. You can't always blame the parents.
As we do not know what he was like as a parent, I think it unfair to assume he was a bad parent because his 30 year old son turns out to be a fraudster. For all we know, he may have been completely legitimate until the temptation dealing with all that money became too much.