Honesty is the best policy. Even though it isn't on your record, if the question is "Have you..." or "Have you ever..." the best thing is to answer yes. You'll be asked to explain it, but if you explain that from this experience you learned a ton from it about fuel management, it shouldn't hurt you. I wouldn't even consider omitting it, regardless of whether or not it is on your record. Remember, the question isn't "Have you ever been involved in an incident we can find" it is "Have you ever been involved in an incident".