- Harsher in Hindsight: Upon finding themselves in a rocket, Doug warns Tony "If this is one of those early Canaveral jobs, we could be blown up right here on the pad." A year later came the Apollo 1 disaster.
- Nightmare Fuel: The fate of the bad guy in "Chase Through Time", who's last seen crouching of the corner of the hive that's home to giant bees that are right coming back - and though our heroes have been flung back into the time stream, they can't get a lock on the villain to send him back to Project Tic-Toc.
- Padding: "The End of the World" ends with a brief sequence of Tony being successfully brought back to the Time Tunnel base, but ten years too early, before he came on the project. It's clearly the result of the script coming in short.
- Seasonal Rot: Didn't get it nearly as bad as some of Irwin Allen's other endeavors, if only because the series lasted only one season.
- Stock Footage Failure: Most egregiously, a rocket takes off in Mercury-Atlas stock footage and lands with Destination Moon stock footage. Do this◊ and this◊ look like the same rocketship to you?
- Tearjerker: From "The Day the Sky Fell In": Tony witnessing his father's death at Pearl Harbor, and telling him the truth about who he is. His father actually believes him, and dies happy knowing that his son survived the attack.
YMMV / The Time Tunnel