Is it possible to give or receive false intrigues from the AI?
Solution 1:
Since intrigue is based on what the AI is likely to do, and the AI changes its mind often, it's hard to say if you could be given false intrigue. The false positive rate is nearly impossible to quantify, and from the player's perspective "false intrigue" and "intrigue that changes" are effectively the same.
For instance, let's say AI #1 tells you AI #2 is plotting a sneak attack against you. You build up a military in response, but AI #2 attacks AI #3 instead.
Was AI #1 lying, and the intrigue shared was invalid? Or was your military response sufficient to deflect the attack elsewhere? There's no real way to tell.
I think the practical answer is that you can be given intrigue that never quite pans out. If that's because the AI rethinks, or because the intrigue was a lie is not really possible to determine.
I have never been in a case where I (as the player) could give false intrigue to other civs. I'm inclined to believe that they play by the same rules - all intrigue given to you is true, but subject to change.