Maybe the next time you sit down with him, you could ask about it. Say something along the lines of "So, how are things going with that girl" and see what is going on between those two. Really, he is the only person who can tell you exactly what he meant by that comment.
Give it time and get to know him for now. If in the end he becomes her boyfriend, remember there are plenty of fish in the sea!
Good luck! (: