Yesterday I discovered another little anomaly with the Oyster system. I ventured out with one of my kids on a circular route taking in the DLR and Overground. We touched in at Crayford and took the rounder service to Woolwich Arsenal. Then it was the DLR to Shadwell with the obligatory sitting in the front seat pretending to drive the train. At Shadwell you have to touch out from the DLR and in again for the Overground and I thought that this would count as the end of the outward journey and the start of the return journey when I next touched out again at Crayford. Unfortunately it didn’t. The main exit gates were closed off so I had to touch out on a dual purpose validator and it flashed up with Entry instead of Exit. This meant I had two incomplete journeys.
So, the moral here is to be careful when ending a journey at an out of station interchange, especially if you end up completing the interchange when starting the return journey.