Why do Claire and Aaron not board a helicopter for rescue, as Desmond foresaw?

Desmond's flashes were often a mixture of confusing visions across multiple timelines. He probably did see Aaron and Claire leave the island because remember... They both did. Only, Aaron left via the helicopter and Claire via a passenger jet (at the very end in the final episode). He was probably mixing these two Обои together and thinking they happened at the same time. Desmond doesn't know exactly when these flashes happen. He just sees them and is forced to interpret them in his own way.

I can think of 2 interpretations of this:

1. Desmond saw a flash of Aaron on the helicopter and a later flash of Claire with an older Aaron in a location which was obviously off-island. He assumed this meant that both would escape on the helicopter, and just told Charlie that he'd seen both on the helicopter because that was a simpler explanation.

2. Desmond saw a flash of Charlie's death and a flash of himself reunited with Penny. He lied to Charlie, knowing that saving Aaron and Claire would motivate him. Possibly he thought there was a chance of saving Charlie, as had been the case with Назад flashes, или possibly he thought that Charlie's death was just inevitable and the sacrifice worth it to reunite with Penny.