Stupidity: Major Franklin is struggling up the side of the cliff while the rest of the group are on top of the cliff checking their equipment, then he slips and slides down the cliff side, breaking his leg. After seeing this, the group members reach for a long length of rope that was used to bring up the other members and the supplies. The commandos could have used the rope to help Major Franklin climb up and prevent him from falling and injuring himself.
Stupidity: When Elena first sees the huge honeycombs in the giant beehive, she tells Herbert that they cannot possibly be honeycombs as they are much too big. Considering she spent the morning watching pitched battles with a crab the size of an elephant and a five meter tall baby bird, don't you think she might have grasped the concept of giant animals, birds, and insects by that stage?