Hopefully he won't bother you seeing that you were not with him for very long. Usually, in my experience with them if their narcissistic ego is hurt/threatened somehow they can become vindictive and stalkish in that they want to find a way to get back at. They will even try to do it through other people. I got to know one pretty well and he was at times obsessed with needing to out do others or find ways to get back at them somehow.

You learned something from this person. We always learn something from everyone we meet in life.