it's always possible that it got knocked, but it might just be a coincidence, but when i was younger nearly everytime my car went into the dealers for something to be fixed, i would get it back with something else needing adjustment, fixing or missing,
if you know something about what your looking for, take a look under the bonnet, make sure the engine is turned off, and take a look to see if you can spot something loose or broken with wire's attached to it, i assuming that you know which bit the gear box is, :D