I just noticed in a game that the AI was keeping up on the tech race, even if at a great disadvantage on research. On a single turn, it seems that one strong AI player would get new weapons tech and suddenly all AI players (even a guy with research 0) would get it too. Also, a shared banking tech with one AI and the other 2 AI got the tech almost immediately.
I have reason to believe no other player participated in this, but just to confirm, is the AI sharing or trading stuff with itself? If so, at a given price or limitations?