AI intentionally trolls human player with religion

So I have alot of wine, and Ethiopia has an embassy with me. I was done making cities and he's kinda far from me so i figure, no problem if he can see where I am. Then he enhances his religion, taking monasteries despite having no wine and no incense and no policies in piety for sacred sites. The only explanation is, he took it just to be an ass.

I hate when that happens, I think I rage quitted few times because of it.

I don't have any wine or incense either on my current game, but my neighbor has a lot, so I chose monasteries too. First because they are a cheap building with good faith & culture yields, even without wine & incense and second because if I don't take my neighbor's capital, I may not see the end of the game (it's Assyria, btw).

He has great land of his own, I'm not his neighbor, he is in no position to take my land, he even had the balls to dof me the turn after enhancing. And that is not a good idea, to just take it because it increases faith and culture generation without the resources it bonuses. There are alot of beliefs that can do that passively, without the large upfront investment of a faith-bought building.

Were the other faith-buy buildings already gone? It's usually a good idea to have something to spend your faith on other than Missionaries and the AI seems to be aware of this.

Maybe the beliefs that would be really interesting for him were already taken, so he went random and it was just bad luck (for you)? In my very little experience, the AI tends to take the beliefs that allow purchasing buildings/units, unless they are really huge on other things that would justify a different belief.