So how did Madoff get away with his $50 billion fraud? Time will tell when and how it started, although I'd hazard the dot com bust. Madoff may have been unwilling to report losses, and assumed (initially) that no one would be hurt if he fibbed if he could eventually trade his way out of trouble. But given the freakish consistency of his returns, it could have been phony from the get go.
The critical bit was that Madoff's firm executed its own trades. No nasty third-party records to diverge with what the customer statements showed.
But another shocker came to light today: the SEC, via its own protocols, should have inspected the Madoff Ponzi operation prior to the end of 2007 and failed to. Why? Evidently, due to Madoff's good reputation in the industry.