These are real hands where I wish I could have a do-over. See the first post for what this blog is about.
Answer: when a competent opponent goes up with Ace on second hand, I needed to pause a bit. Right play is to discard a diamond on the Ace of hearts, and then there is no cross-ruff available to the opponents. West made the smart play of refusing to ruff in front of dummy with the King, so I put the King with East and that led me down the garden path.