1) Pressing interact twice or more (E on PC) quickly to pick up an item puts you into a stutter/wobble mode. Probably trying to pick up the item that is no longer there, failing and repeating. Opening and closing your menu fixes it, but that's not fun to do when kiting.

2) If you run out of ammo, and hit overcharge to reload, when overcharge ends you 'double reload' using up 2x the ammo and the animation taking twice as long. Almost always fatal.