I once saw Azelf in OR keep on spamming Nasty Plot, Extrasensory, and Future Sight against my Mightyena even though Azelf was already at +6 for SpA.
That's very odd since I looked up what the fourth move would be and it is Uproar, which can damage Mightyena.
Here's what the AI must have been thinking in a battle I just had:
"Okay, I have a burned Focus Sash Cloyster and I have pulled off a Shell Smash once. My opponent has a Rotom-Wash with about 60% HP. What should I do...I know, Shell Smash again!"
Also, I noticed a weird quirk:
As we can suspect, the AI cheats when it uses Wobbuffet. If I use a Physical move, it will always use Counter. If I use a Special move, it uses Mirror Coat. It just knows. But, if I use a status move, it will use...Mirror Coat. And I checked, it doesn't even correspond to old type-based damage catagories (i.e., I use a Normal-type status move, it still does Mirror Coat).