The decision about which side of the mountain they wanted to track up was inconclusive as half the students wanted to go up one side, while the other half wanted to go up the other side. They discussed the option of doing just that, sending half the group up each side of the mountain.
But after seeing how effective they were as a single unit against a powerful beast, they felt that it was best to keep everyone together in one powerful group, just in case something similar happened again.
So eventually, they started to travel up on the left side of the mountain. Del had made the final decision and was ordering the group around. But curiously he wasn't the one that was leading at the front of the group, instead some of the stronger teams had their own individual front liner.