When they are attacked at the waterhole, Guido is suppose to fire at an incoming horseman. But when he takes aim, the rifle bolt is in the open position which makes it impossible to fire. Yet he manages to fire anyway, and in the next shot the bolt is in the locked position
Lefevre is photographed for the machine gun demonstration against his will, thus leading to his discovery. One of the few guarantees afforded legionnaires is anonymity, and it is specifically forbidden for a legionnaire to be photographed without explicit permission.