I frequently engage enemy vehicles while firing from hilltops or behind terrain.
As such, after firing the RPG-42 especially, I drop to the ground to dodge machine gun/grenade fire and avoid being spotted.
However, from this position, switching to either weapons or the binoculars while laying down cause the character to stand straight up before performing the action, usually resulting in me getting shot.
Reloading, too, causes the character to stand up instead of popping up a message that says "cannot reload while laying down."