They could be in danger of other hoolies go to the cave and find bits and pieces of their kind, (because Beast 11 killed the ones in the cave) they would probably get mad and kill anything that they suspect might have done this.  Wouldn't you get mad if someone killed humans and you found bits and pieces of the humans?  If the hoolies track down Beast 11, how would the trio be protected by the natives when they and if they find them?  The trio also might be in danger because they could get killed as suspects of the hoolies, or just for lunch.         If they had just made friends with the hoolies, then they wouldn't be in this danger.