Stupidity: In the original novel, the attempt on Mrs. Doyle at the temples was made rolling a boulder off a cliff. In this adaptation, the culprit is said to 'dislodge' a large stone from the temple; you can however see that the stone is already dislodged and sticks out from its place on the pillar, and he had no way to know that the Doyles would be in that particular spot, making this attempt to Linnet's life rather nonsensical (requiring also herculean strength, no pun intended). (00:47:40 - 01:39:30)
Stupidity: After going through being stuck on a deserted island for 15 years and finally being rescued and brought back to civilization again, you would think if Skipper was going to sail out with the castaways on his new Minnow boat, he would pick an enclosed lake this time as opposed to the open ocean – now they got stuck on their island again because of that decision.