What does that phrase even mean?
Lay was a thief and stole millions of dollars and seems to have paid, in some way, for his crime.
The fact that I think car thieves are despicable and should be prosecuted to the fullest extent of the law doesn't mean that I feel particularly sorry for the guy who left his car unlocked with the keys in the ignition in the worst part of town at midnight.
Mass criminal is pretty much self explanatory.
Mr. Lay did his crimes on a mass scale in that his crimes affected masses of people.
As for the other, you seem to be attempting to diminish the culpability of a criminal by defaming his victims.
Mr. Lay in no way paid for his crimes in this life just because he went to the next life.