They have been on the road for a number of hours. Theo is starting to gain hope that the State Security Police might actually not be looking for them: after all, Gascoigne did not know about the baby. They are forced to stop when they see a tree fallen across the road.
When analyzing a source historians want to remain NEUTRAL in other words they don't want to be PERSUADED by personal feelings and options they know the different sources may reveal different OPINIONS