Testing ahead of Facebook’s highly anticipated IPO offering did not detect any of the glitches that interfered with the social networking site’s public offering on Friday, said Robert Greifeld, chief executive of Nasdaq OMX Group Inc., two days later. “This was not our finest hour,” Greifeld said, while acknowledging that the Nasdaq board had met Saturday to consider the Facebook offering. Greifeld said the first day of trading was “successful” and that withdrawing the IPO never came into consideration. The offering started off Friday morning with a 30-minute delay and technical glitches throughout the day that forced uneasy traders to cancel orders over confusion of what they had bought or sold, and at what price. Nasdaq plans to make changes to the IPO auction process.