Trips can be picked up and swapped multiple times. What is the code next to the trip in the N3D. You are just seeing the history of a sequence as it gets passed between someone and open time. Also do N3DR which will show how the trip became open. I'm guessing the trip you are looking at was assigned to someone with a composite or relief line. If it was under the N3D it will have BO as the code. Then they found a better trip to trade for so under the N3DR you will see TT or OO if they automatically or manually trip traded away. Or if hell froze you'll see a DT for a drop.