I would argue that it is [highly] unlikely. Take a look at how we as a civilization have developed spaceflight:
The first rockets were created in China hundreds of years ago. They were little more than rods with gunpowder, but they were pretty powerful - although nothing like what we have today. What did humanity proceed to do with gunpowder? Use it for weapons. Once people realized how effective it was at launching projectiles, they realized how effective it was at launching projectiles at other people. Since then, gunpowder hasn't been used for spaceflight - at least, not outside novels by Jules Verne!
Flash forward quite a few centuries. The first "modern" rocket was designed by Robert Goddard in the 1920s. While his designs never had a huge influence on the course of rocketry, it certainly was a starting point for the future. A future where the development of rockets was - you guessed it - used for war.
Werner von Braun has gone down in history as a controversial figure, politically and scientifically. He was the primary developer of the V2 rocket, which was used by Nazi Germany in the Blitz. Later in the war, however, he and his collaborators defected, and the United States took them (with Russia taking many technicians). This was the start of the space race.
ICBM development was one of the defining factors of the space race and the Cold War. It was behind the idea of MAD (Mutually Assured Destruction) and was a huge deterrent to nuclear war. Large rockets could also be used to get people (and things) to outer space, though. Bigger missiles meant bigger (peaceful) rockets, and better ways to get to space.
So my guess is that the easiest first way for a civilization to get off their home planet would be via rockets, and that they would soon figure out that rockets have some other (more devious) purposes.