Sometimes a difference is intended "for the better", but coders can miss a use case, so don't hesitate to report it if you see such change as a setback.
Here, when aliens don't bleed, I don't see any practical use for using medkits. On the other hand, if you're standing ON a stunned alien and looking at a hurt friend, you want to target the friend - so it's a good thing that the alien is not considered the target of your action.