Goofs

When Virginie is calling on her mobile phone in the Gendarmerie, it can clearly be seen the phone is not calling anyone at all.

The metal detectors used by the men searching the forest sound like Geiger counters (clicks getting faster when approaching a radio-active source) and not like metal detectors (sinusoidal sound of higher pitch when approaching a metallic source).

The sign of the Gendarmerie on the several types of uniforms are shown with Helvetica. But on their building and their cars is imitated with Arial font type which was developed for early Microsoft products to visualize the Helvetica font type on low screen resolution without having its license.

The two men walking through the forest with metal detectors are holding the coils too high off the ground to detect anything and they aren't swinging them back and forth. Also, one of the men is following directly behind the other, and therefore wouldn't detect anything the leader didn't.

Thierry stops the cargo van in the forest, gets out, and instead of walking down the driver's side to the back, walks around the front of the van and down the passenger side to get there.