New diplomatic AI post-patch or post Bhruic?

[Ari]

Playing as the Dutch (prince/continents/large), I was gradually founding cities ever closer to Hannibal. We were both Jewish and had been for a long time, with peaceful relations, and open borders. We had been trading resources and tech and he was at something like +10 for me (pleased). Eventually he founded a city in the midst of a few of mine (2 tiles away from where I had been going to found one, the fink). Strangely, about 10 turns later, he "liberated" the city and transferred it to me. When I looked at the city, it was 100% Dutch, though I don't know what it had been before. As far as I remember, I don't think it had been anywhere near 100% Dutch territory before that. Indeed, it's possible that the city was 0% Dutch before that (actually, it would have to have been when the city was founded). Given that I was creative and surrounding him, it's likely I would have flipped the city eventually, and it's possible he realized that, but it would've taken a long, long time, and would certainly have been stoppable. Incidentally, I was both militarily weaker than Hannibal and at best technologically on par (actually, I was probably behind him).

Anyone ever see a friendly civ spontaneously hand over a city before?

Also, much later, on the diplomacy screen, I saw that I had a +1 with Hannibal for having traded technology with him, something I've never seen before in any game I'd played. I'd traded techs with him, but had never handed anything to him either when he begged or on my own.

Has anyone seen either of these things before? Could this represent a slightly different way that the AI deals with the player?