I always disliked it when I was picking up something with E that my weapon would automatically reload. Or something like that...it's been a while. Basically, the reload key should reload only.
Yeah, that's a popular console mechanic. Since gamepads don't have enough buttons, shooters usually map "Reload" and "Pick up weapon" to the same button, with the latter being triggered by holding the button for a short amount of time. It's pretty clunky and absolutely unnecessary on PC where you have a wealth of keys available.