True to what Grandpa said, only three days later, the same guy returned but only to drop off someone who would watch their camp constantly.
Because they were prepared and ready if someone decided to attack, a few of the camp residents noticed their arrival and the immediate departure. It made them doubt what they were thinking.
They were having lunch at the time, and everybody was made aware of the situation. They all agreed to tone down their activities if they were in the observer's line of sight. They guessed the man was someone who was farsighted. That was because he was left pretty far away from them, and he didn't try to get closer to them.
Time passed, and they got used to someone watching their every move. It wasn't like they hid everything from the man. They did everything as usual. They went hunting, practiced their blade throwing and bow use, and they also played the game every third day.