For a laugh, apparently:

The soldier was being escorted back to the US for disciplinary reasons before they turned around at the airport and joined a border tour, an official tells CBS News

A witness who was part of the same tour group tells CBS the soldier laughed before running towards North Korea

The show reached a point where they'd surpassed where the books were in the narrative and things fell apart. The political intrigue, backstabbing, and subversive nature of the story was done away with in favour of forcing plot points through to get everything wrapped up, with no consideration made on why those characters would act in the way they did.