Madoff spent some time getting his ducks in a row before turning himself in. He had a few shredding parties at the same time his cronies were socking away some serious cash. Even though he was "working alone",
his cronies had a bit more time to break those incriminating ties with him, or try to.
With the noose tightening around his scrawny little neck, Berg didn't plan as far ahead as Madoff did. He was probably too arrogant to believe he'd be caught so soon, (or caught at all) which is fairly predictable, given his Narcissitic Personality Disorder. Which left Berg's cronies less time to get to their own shredding parties underway. Bad timing, incriminating documents and angry investors are an explosive recipe when it comes to obfuscating evidence. To cover all their bases, Berg's agents and his other minions began to silence dissenters with threats.
Look for similarities between Madoff's alter-ego Ms. Kohn, who "
was paid $62m in kickbacks from a special fund at Mr Madoff’s New York brokerage for recruiting investors." and Berg's own agents and legions of financial advisors. They didn't work for nothing and they aren't the types to easily walk away from kickbacks.