Discussion early on centers on finding a new source of drinking water. In My Friend, Mr. Nobody (1965), near the cave where Penny's friend resided, the area is lush with vegetation and contains a large pond or lake with apparent drinkable water. This is within walking distance of the Jupiter two camp.
Fairly late in the show, Don uses the "jet pack" to catch up with everyone. In the first clip of his landing (a "wide shot"), he has a very dark jacket on. Yet, in the close-up of his landing, he is wearing a medium-colored jacket.
At one point, Will and Dr. Smith come across a stream running down the side of a rock. Dr. Smith tells Will the stream is caustic and will take the skin off his hand. When Will doesn't believe him, Dr. Smith dares Will to touch it. As he repeatedly approaches and hesitates, splashes of water become visible on Will's right hand and sleeve.
Even though Professor John Robinson and Major Don West do not trust Dr. Smith, he is somehow allowed to walk around with a laser pistol and then no one even questions him when he returns to the encampment without it.
At approximately 43 minutes into the show, as the Robot approaches the alien spaceship, you can see the actors legs instead of the two metal caterpillar 'feet' typically seen on full shots. There is also the power cable that is feeding power to the lights in the dome.