Yesterday I traded some tech with an AI player, successfully, then I realized that this was the very same player I was in the middle of attacking.
This made me think that the automatic 80% chance of an AI player trading a tech with you was flawed as they would happily trade with a player who was attacking them.
If each AI kept a tally of the players taking stars from them they could use that tally to modify the chance of them trading. Maybe every star you have taken from them could reduce the chance by 10%.