Usually the scout would already know your sons name and year. If not he would usually ask the coach. But sometimes in the interest of time and effort they might just ask someone in the crowd. It sounds like this might have been a bird dog (associate) scout. However, either way it's always good when they show interest in your son. Yes, if he really likes your son enough, he (the scout) will keep track of him. Possibly make a note to be sure to see him the following year. None of this is for sure, but it's all good.
Best of luck!