Gaffes

When the guerrillas are crossing the Rio Grande, one guerrilla, armed with a bolt-action M43 Spanish Mauser, is shown in a close up raising it over his head. When the camera switches to a close up of the guerrilla in front of him (armed with an M1 Garand), he is seen doing the exact same motion, down to how his equipment jostles, in the background.

At his execution, Che was shot a total of nine times, not three as shown in the movie.

When the Bolivian troops are about to ambush the guerrillas crossing the river, you can see the bullets in the belt have primers that have already been fired. The firing pin imprint on the cap is clearly visible.