0.90.10 (EDIT) Non squad members can't be healed.

[BoogieMan]

I saw an NPC Plastic Surgeon who happened to be a Skeleton try to walk into a Holy Empire town and got beat down by the guards. I picked it up and carried it away and tried to repair it with a robotics kit. It drains the repair kit, but does not repair or heal them. It was unconscious at the time. I haven't had an opportunity to try on a conscious but still injured one.

It does work on player Skeletons either way, however.

[BoogieMan]

Turns out it doesn't seem to work on anyone not in your squad. I also tried it on a unconscious escaped servant of the Holy Nation, no healing received.