Arms Race Map AI issue

Not sure if I should post this question in here or in bugs...

I have had some confusion with the AI diplomacy stance in the Arms Race Event map. I understand how the global relationship standing works and am usually very aware and conscious of this to gain an advantage on all the games I play.

The issue is I did not declare war on anyone but had been surprise attacked by two human players which is understandable and fun to defend but then surprised attacked by two AI players as well? Does this seem legit on that map?