Sorry, I couldn't help overhearing, did you mention something about...
对不起,我无意中听到你们的谈话,你们是不是提到...
and you avoid the frustration of arriving at the very moment when the train is drawing out of the station and being unable to get on it.
而且可以避免那种正好在火车驶出站时赶到车站,因上不去车而感到的沮丧。