The AI just cast a Corrupt on a Giant Tortoise, which would kill the tortoise. But while it was on the stack, it also targeted the same Tortoise with Coumbajj Witches. This just tapped them down and let me ping it. I've seen similar behavior with other cards.

Also, I've seen the AI activate Coumbajj Witches targeting it's Runed Servitor in it's post combat main phase. It achieved nothing and looked bizzare, but next turn it did the same thing, except in the pre-combat main phase and then attacked with it. I suppose it's "AI sees cards it would draw" fallout, but the first post-combat instance was extra crazy.