why is that a bug?
if i have a wounded/bleeding base commander i want to heal him (+stun afterwards) to survive the next rounds until base is cleared - to bad one cant check for wound with already stunned aliens
(if the option is off (=my config) one do not have this problem)
I'm 97% sure I heard the devs claiming this is not/should not be possible, so it's a bug to me.
As for the reasoning, aliens have alien anatomy, so I think using human medicine on them (I mean chemicals, not just bandages) would be a stretch, and also a bit painful to the game's atmosphere.
However, using medikits on civilians should be allowed (though AFAIK it shouldn't work at this point, unless someone's fixed it).
(Please bear in mind it's all based on memory, so please don't crucify me if I remembered something wrong.)