Amusingly the first line of the superb season two episode Downloaded is:

There has to be another way out of here!

This is said by the Joker (Baltar) to the woman who has stolen her way into the defence system and his heart (the thief) as his house is about to be nuked.

What does this mean? Absolutely nothing. There's no evidence to suggest that RDM chose "All Along the Watchtower" as the theme song for the Final Five until well into the third season. But it's fun to note.

It's also true that several official sources have stated we should not treat this song as having come from 1967 Earth, it's just music in the show which, like all music in all TV shows, is of course written by Earth people. However, I am amused to note that my invented backstory actually does explain it. In it, I hypothesize that the Final Five are beings from 21st century Earth possibly uploaded from living humans. As such, they might well have been alive in the sixties and become attached to the music of their youth, thus picking it as a trigger song. This is in contradiction to RDM's statement that Cylon bodies are originals rather than copies of living humans, but I would not thing that applies to a human who deliberately uploaded to become a machine mind and copied their own body. But again, this is just a supposition for fun, not likely something to be true.