um no it doesnt work like that it's a mini series NOT season 9 so nothing comes before it and nothing comes after it
think of it like a spin off yes it's connected to the main show but there isn't an order
What if there was a season 9 but no season 3? Would that make 'back to earth' season season 3? No it wouldn't..
Series: "a set or sequence of related television or radio programmes."
Columbo is marketed and sold as "The Complete Series" by the distributor. The films are sorted into 10 distinct seasons even though each film can be watched more stand-alone than a TV episode. Compiled, however, they do form a series.
X-Files: The Event Series is a continuation of the previous series, so technically it is a 10th season. I don't see why a long break since season 9 makes any difference to the numbering. They still form a logical progressive order.
That makes X-Files and Columbo each a series in my book.
I expect Walker: Texas Ranger and Hercules are considered separate pilot films,
How to Train Your Dragon films are not considered part of the Dragons animated series even though it is canon and they fit into the timeline.