A newspaper report refers to "former British Army officer, Sergeant Brewster". Sergeant is an NCO (Non-Commissioned Officer) rank, not an 'officer' rank.
Despite the large rucksacks everyone carries, supposedly holding ropes, tents, food, even bottles of beer, none of them has any weight. At one point Carla scrambles up a near-vertical slope and her pack bounces off her back as she reaches the top. Probably a good thing, though, as some of the group decide to run while still carrying these loads.