From BBC News:
According to Mr Rodriguez’s version of events, the atmosphere was so friendly that Che willingly agreed to the photograph and even laughed when Rodriguez said: “Watch the birdie, Comandante”.
An hour or so after the photo was taken, Che was killed.
Felix Rodriguez received the order from the Bolivian military high command. There was a simple code: 500 meant Che Guevara, 600 dead, 700 alive.
500 – 600 was the command.
Mr Rodriguez wanted confirmation on the crackly radio line. It was repeated: 500 – 600.
Mr Rodriguez broke the news to Che that there was to be no trial.
“Che turned white… before saying: ‘It’s better this way, I should have died in combat.’”