Also, you should know that some people have a weird way of saying, "Goodbye." Sometimes people don't like to say goodbye for the reason that they know they will return at a later time. So, instead they make it so that they are not welcomed anymore - by either losing respect or doing something they are embarrassed to come back to.
For example, while working at McDonalds (yes, I was one of those type), I knew that I never wanted to come back there again, but I thought I would have to if I just left there without doing something bad. So, what I did was called 10 minutes before and told them the place sucked and the manager got really angry and called me a huge failure and said someday I will never be successful. I was happy, because 1) I got to quit, and 2) I knew there was no possible way I can go back there and I can look for other jobs.
So perhaps that's what he did.