1.) When you heal someone who was stunned while being on a stationary machinegun (like the one on the EV), they will not be able to do anything unless they kill themselves. Not even shoot.
2.) This when joined http://imgur.com/b39hShi
3.) When sometimes trying to throw grenades, healing/ammo packs or grenades/airstrike marker, the merc will make a ‘throw/give’ animation, but won’t actually do it.