I just saw a player send a captured specialist to it's owner, and I don't know how it could have happened. Here are the details:

Player 1 had a mine with player 2's captured assassin. Player 1 then sent a sub with the captured assassin and nothing else to player 2's outpost. Once it gets there, the assassin will reactivate for player 2. I see player 2's entire base, and he hasn't had any diplomats (although he does have one available to purchase from his queen). Even if there was a diplomat involved, wouldn't the sub be in player 2's color, with the assassin being released immediately upon leaving the outpost?

Was this a bug, or is there some way this could have happened that I'm not thinking of?

There is an option to release captured specialists back to their owner.

If you are holding a captured specialist, you have the option to release it (perhaps a diplomatic agreement was made). Upon being released, the specialist is still in a captured state in the color of the player who released the specialist. Once that sub returns to an outpost that is owned by the original owner will the specialist be activated.

The original owner can also send a sub to target the returning specialist to regain ownership of that specialist. Especially handy if the specialist has a global ability like a King.

Wow, I didn't know that. Maybe it was in one of the tutorials and I forgot? I guess I don't see the option on my captives at the moment cause their owners are eliminated.

Thanks for the info!

Ah!

If the owner is eliminated then you can't release the captive specialist!

That's why you didn't see the option too.