I'm wondering if that refers to the plane's departure time, and subsequently the arrival time.
FlightView says that the plane was scheduled to depart at 1:35 PM (presumably local time), but actually departed at 3:29 PM.
It is estimated to arrive at LAX at 5:47 PM (local?), but was scheduled to arrive at 4:05 PM.
Perhaps they had some sort of delay back in Paris, attributable to security, but cleared the plane for departure after all? Then, while the plane was enroute, they discovered some new information?