Better security than it sounded at first

Ben Evans has an AP article about another univited-guest incident at the White House:

A Georgia couple who showed up at the White House a day early for a tour somehow wound up at an invitation-only breakfast with President Barack Obama and the first lady. It wasn't a state dinner, but it left the White House once again explaining how people who were not on an event guest list wound up being ushered into the presidential mansion anyway. This time, White House officials say they were simply being hospitable.
The improbable adventure of Harvey and Paula Darden, Obama supporters from Hogansville, Georgia, took place on Veterans Day, two weeks before Virginia socialites Tareq and Michaele Salahi infamously crashed the Obamas' state dinner for the prime minister of India. The Dardens mistakenly showed up a day early for a tour scheduled through their congressman. The White House and Secret Service both said the Dardens went through the appropriate security screenings and were allowed into the breakfast as a courtesy because there were no public tours the day they arrived.
That explanation was news to Harvey Darden, 67, a retired pharmacist, who said he and his wife thought they were starting their tour and weren't told about the change until they were ushered into the East Room, offered a buffet spread, and told they'd be meeting the president.
"The further we got into the White House, the more surprised we were," Darden told The Associated Press in a telephone interview. "My wife looked at me and I looked at her, and I said, 'You know, I don't know if we're in the right place.'" They approached a White House aide with their concern that they had veered off course but were told to "just go with the flow," Darden said. "I felt kind of funny because I was the only man in the room that wasn't dressed in a coat and tie," he added. "I was just a plain tourist."
Secret Service spokesman Ed Donovan said agents performed the same screening procedures on the Dardens that were used for other breakfast guests: they checked the Dardens' names and did a criminal background check, steps that were not taken for the Salahis at the state dinner.
Because the Dardens were able to pass Secret Service vetting, they were allowed to attend the breakfast for veterans as a "nice gesture," White House spokesman Nick Shapiro said. He added that it's not unusual for White House staff to take people who are cleared in for tours to other events if there is space, including Marine One arrivals, East Room events, and Rose Garden ceremonies.