When Manon visits her father's grave, a gravestone falls over on the bottom right-hand corner of the screen.
When Cesar lies 'apparently' dead, Amandine enters the room, opens the drapes and checks on Cesar. She blesses herself, and then there's a zoom-in on Cesar's hand wrapped in a rosary. His fingers twitch a few times.
Near the beginning of the film, when Manon plays the harmonica in the rain at the graveyard, it is obvious that the song she is playing does not match her playing position. For example when there is a high note, on screen it looks like she is playing a low note.
When three goats are climbing on the rocks, you can clearly see someone waving a pine branch behind them, probably to force them to move.
When Ugolin is hunting around, you can see a crewman duck behind a bush after releasing the rabbit Galinette chases.
When Manon talks to the teacher in the field, she says the rocks 'are Cretaceous, they're all from the Quaternary'. These are two separate geological time periods.
When the wedding guests pose for a photo, the camera is much too close (about 4 feet away) to capture the group.