“Apparently, its a crime to keep a large sum of money in your home even when you haven’t done anything wrong.”
He had drugs.
Well, it apparently wasn't enough to get him arrested, and there apparently was no evidence of selling, which would explain having a large amount of cash.
But, your statement is exactly what is wrong with the "War on Drugs"; it's a justification for everything.
So if you have drugs in your home, the feds are entitled to all of your assets?