3 things. Firstly, the AI won't play a Shard of Wisdom on a Voodoo Doll. I don't know if it's because the Doll has 0 attack, or that it doesn't know that you can play them on non-Quinted creatures but, either way, it doesn't.
Secondly, the AI will waste Shards of Bravery when the player has a Sanctuary out.
Finally, the AI won't use a Cremation on a Phoenix, even though it's often a sensible move.