Personal Accountability is about more than just admitting you were wrong. Sometimes it's about admitting that you didn't have enough information to make a definite choice. In you hypothetical situation while you didn't do anything wrong you still had something to learn.
If you don't look back and see what information would have allowed you to pick B and instead go oh well, there was nothing I could have done differently. Guess it was just inevitable. You will miss an opportunity to learn and possibly do better next time. That missed opportunity is an example of arrogance in action.
I also think it's ok to look back and believe you made the best decision you could have given the information, and that you simply got it wrong (and that it's ok and understandable). And that while you may have gotten it wrong, going another route still wouldn't have necessarily been the best decision due to risks vs rewards.
If you don't look back and see what information would have allowed you to pick B and instead go oh well, there was nothing I could have done differently. Guess it was just inevitable. You will miss an opportunity to learn and possibly do better next time. That missed opportunity is an example of arrogance in action.