Here's GPT-5's response:
me: which is the best of the following 9 items: 1. bear, 2. car. 3. plane, 4. house, 5. high-rise, 6. church, 7. boat, 8. tree, 9. truck, 10. duck.
GPT-5: Thought for 11s. House. It provides essential, lasting shelter and broad utility. Note: you listed 10 items, not 9.
edited: i saw someone mention that the chat interface doesn't repeat the results you get via API.
1) one-shot the result, chatting isn't an option; so it is trying to figure out what to do to accomplish its goal.
2) with subtle inconsistencies. My example was mostly an illustration, I don't remember the exact details. Unfortunately, it has been too long and my logs are gone, so I can't give real examples.