Behind Stanford's Back?

Stanford's number two man, former CFO James Davis, will plead guilty to the charges leveled against him. Stanford's lawyers respond by claiming that Mr. Davis acted without Mr. Stanford's knowledge (via Houston Chronicle):

“If Mr. Davis committed crimes, it was without the knowledge or approval of Allen Stanford, and Mr. Davis will have to answer for those crimes,” DeGuerin said. “It is human nature for a criminal to try to shift the blame for his own conduct in order to make a deal with the prosecution for a lesser sentence and to escape full responsibility for his crimes.”

Let’s assume for a second that Stanford had no knowledge of any wrongdoing by Mr. Davis (which, in my opinion, is highly doubtful). In such a situation, wouldn't it be grossly negligent of Stanford to have no knowledge of activities related to the core business of Stanford Financial Group?