The Dropout - S2-E1
Other mistake: When Greg is in the kitchen getting ready to leave for the baseball game, there is a number 53 on the back of his jersey. In the following scene at the baseball park, there is another man with his back turned throwing practice balls, who also has the number 53 on the back of his jersey. It is clear that it is not the same person.
Other mistake: When Mike calls home from the office on the rotary dial, his finger dials only two possible numbers 3,4 repeatedly. Not 762-0799 or 555-6161 the two numbers that the Bradys had during the run of the show. (00:17:15)
Answer: Much trivia has been written about "The Brady Bunch, " including the various interrelationships and dynamics among the members of the cast. For example, much has been written about why Robert Reed's Mike Brady did not appear in a couple of episodes, including the series finale, due to rancorous creative and artistic differences with series creator, Sherwood Schwartz. However, in contrast, I have never run across any reasons given why a particular child did not appear in specific episodes - only that the episodes were missed. This suggests the causes were likely unexceptional, such as illness, injuries, vacations, or real-life family obligations.
Michael Albert
Although those options ARE possible reasons, it just seems a bit ironic that this happened all in Season 2 ONLY and within a short amount of nearly consecutive episodes. Never happened during the other 5 years of the show at all.