I have played part way through a GC for the Entente and so far germany has:
1) Inflicted a severe naval blockade......on ITSELF!

2)Removed the French Shock tactic (thus improving France's defensive ability) immediately prior to attacking France.
3)Stole plans for the western front twice in one turn (effectively wasting one event)
I do understand the reason that a player can pick events that would be good for the enemy (thus preventing the enemy from playing them and gaining the benefits) but The AI seems unable to realize that some events are detrimaental to it, or indeed, as in the case of number 3 above, that the events can "double up"
Basically from what I can tell the AI seems to merely pick events at random and then plays them at random with little ability to judge their effect.