so, i was playing today with that lady who has shopping bags in her hands, When I shot a tommy while standing up on a car with AUG, it automatically crouched and started to shoot. I thought, I did it by mistake, but It keep happening, then i realize its wasn't me. If you're on ground or some thing you crouch and tries to shoot it gets back on foot and shoots with that wep called AUG (Not sure if this happens with all custom weps), but if you stand up on a car and then tries to shoot it crouch automatically. I also recorded a video with a software which keys are pressed and you can see i ain't pressing my C key which is for crouch but it crouch and shoots.
https://youtu.be/BrclxX8aXZscheers.