Hole in One - S4-E3
Continuity mistake: When Rodney says "yeah he did. The landlord.", in reply to Solly, he has a glass up to his mouth. In the next shot, he has obviously just swallowed what was in there, the glass is back on the table and you can see his cheekbones moving.
Hole in One - S4-E3
Continuity mistake: At the begining of the episode, there is a box that is by the table Rodney is sitting on. A little later, Albert and Del come and open that box. The box disappears and then reappears between shots. (00:02:05)
Chosen answer: An apparent long string of illnesses.