in December 1496, after a rainy day, an inn somewhere in the Black Forest, on one of the major north-south roads, was visited by a group of highwaymen in the middle of a freezing cold night. Fortunately, a band of adventurers present at the inn managed to fend them off. Because of the bounty on the highwaymen, they wanted to pursue, but the highwaymen had set fire to the stables, and their help was needed to save the main building.
After several hours, the fire was put out and the animals were calm enough to pursue the highwaymen, who took off with several of the horses. However, due to the frozen ground, there were no tracks to follow. Still, the master tracker of the group wanted to try his luck. While trying to find tracks, he suddenly slipped on a slippery patch of ground near the south exit and fell on his rear. When he stood up again, his pants were wet.
He then went back to his group and told them he knew where the bandits were headed. They went after the gang and soon caught up with them.
How did he know where the bandits were headed, and what direction did they leave in?