In the opening sequence Adam is shown wearing a tan shirt and then a black shirt. Little Joe has a black hat and an off white shirt and then an off white hat and a tan shirt. In addition Little Joe is riding a different pinto horse when his clothes change.
When Hoss gets back to the Ponderosa after being attacked by the three men, Adam asks Hoss who did it. Hoss replies it was Doud and the other two fellas from Mount Pilear. Hoss couldn't have known Doud's name because when they met (both in the drug store and when the men attacked Hoss), Doud's name was never mentioned. The only time his name came up is when he told it to Adam as they returned Joe's horse to him. This was after Hoss had left for the medicine.
After receiving a wire from Hoss stating that Little Joe was critically injured and that he and Adam were treating him, Ben storms into the house pistol blazing encounters an older gentleman and a young woman and starts calling for Joe, not Adam or Hoss which would be the expected response.