How did stubbornness nearly cost Arliss his life in chapter five?

Travis tells of the time Little Arliss grabs a fish that Old Yeller caught. The fish stabs Little Arliss with a fin but even though he is in pain Little Arliss won't let go of the fish. After Mama medicates and bandages the wound with a poultice then Little Arliss tells a tall tale about how he got the fish from under a big rock and almost drowned bringing him to shore. Mama lets Little Arliss tell the story but Travis thinks it is wrong of Little Arliss to tell such big lies.