He said that under oath after being subpoenaed to testify before a senate subcommittee (or was it the House). It should be not very difficult to show beyond a reasonable doubt that he knows exactly where the money is. Up to that point, he may not have done anything illegal, but nevertheless an unconscionable act in complete disregard for his clients safety. Now he could face a perjury charge.
It is often not the act itself that gets these fat cats in serious trouble, but the lying and cover-up, ala Lloyd Blankfein, Richard Nixon, etc.
