Bloomie's intentional ignorance.

This would be why Judge Weinstein, who has a history of coaching anti-gun cases to proceed, won't let Mayor Bloomberg testify:

NSSF noted that perhaps the mayor’s insults stems from his self-professed ignorance of our nation’s firearms laws and regulations, business practices of firearms retailers and the duties of the ATF. “I don’t know what the law is and what procedures are,” responded the mayor to a deposition question on illegally purchased firearms, NSSF quoted him. “I have no knowledge of what appropriate safeguards are for a dealer to comply with the law or what standard practices are in the arms business,” they quoted him.

In the same deposition Mr. Bloomberg admitted he did not know that ATF conducted inspections of firearms retailers. “I didn’t even know they had inspections,” the bewildered mayor offered and Bloomberg also noted that he did not know what a Federal Firearms Transaction Record, commonly known as a Form 4473 was or a NICS background check.