Bill Cohan, author of "Money and Power: How Goldman Sachs Came to Rule the World," spoke this morning to Bloomberg TV's Margaret Brennan this morning, saying that "Goldman's culture has gotten off the tracks" and that Greg Smith's career on Wall Street is "toast" after writing an Op-Ed in today's New York Times.

On Goldman:

"Goldman's culture has gotten off the tracks. They espouse this idea of the client comes first but in fact, we know time and again, whether it's the Abacus transaction or a number of other things that they did in the financial crisis beginning in 2006 when they put the big short on and they continued to sell mortgage-backed securities to their clients at par, that Goldman has been putting itself first."

On Greg Smith:

"He obviously knows how Goldman treated derivatives clients and he knows what he did with his own derivatives clients. Whether or not he understands the Goldman strategy overall, he's not on the management committee or even a partner of the firm. I'd never heard of him before, not sure what that means. But the point is that he knows what he knows and is obviously frustrated."

"He's toast. He is completely toast in terms of Wall Street, no question about that. He is in the witness protection program right now."